RU2439842C2 - Thermal noise overshoot based scheduling in wireless communication network - Google Patents

Abstract

FIELD: information technology.

SUBSTANCE: request for connection and reserving quality of service (QoS) resources can be combined in an access message on an access terminal. The access message with the combined communication signals can then be transmitted to an access network. An application layer message (e.g. data over signalling (DOS)) can also be combined with the connection and reservation request in the access message.

EFFECT: improved scheduling affected by cross talk between uplink transmissions from different user devices.

45 cl, 9 dwg

Description

I. This application claims priority under 35 U.S.C. §119

This patent application claims priority for a provisional US application with serial number 60/890418 entitled "ROT Based Scheduling in W-CDMA Uplink," filed February 16, 2007, a provisional US application with serial number 60/913789, entitled " ROT Based Scheduling in W-CDMA Uplink, "filed April 24, 2007, and US provisional application Serial No. 60/913778, entitled" A Method to Estimate Rise over Thermal (ROT) in W-CDMA, "filed April 24, 2007 filed by the submitter of this and expressly incorporated herein by reference.

FIELD OF THE INVENTION

The presented description generally relates to communication and, more specifically, to technologies for performing user scheduling in a wireless communication system.

State of the art

Wireless communication systems are widely used to provide various communication services, such as voice, video, packet data, messaging, broadcast, etc. These systems may be multiple access systems capable of supporting multiple users by sharing resources available to the system. Examples of such multiple access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal FDMA systems (OFDMA), systems Single Carrier Frequency FDMA (SC-FDMA).

In a CDMA communication system, several user devices (UEs) can currently transmit on the uplink to Node B. Transmission from each UE is an obstacle for transmissions from other UEs to Node B. The quality of the received signal from a given UE may depend on several factors. such as the amount of transmit power used by the UE, losses in the transmission path from the UE to Node B, the number of mutual interference UEs observed at the Node B, etc. The quality received from the UE can be improved by increasing the transmit power of the UE. However, the increased transmit power of the UE will increase the amount of interference for other UEs, each of which may need to increase the transmit power to maintain the desired received signal quality for that UE. UEs may be periodically active on the uplink and may occasionally transmit at any time when there is data to send. For the UE, uplink transmission scheduling can be performed at any time when they have data to send. Scheduling may be difficult due to mutual interference between uplink transmissions from different UEs.

SUMMARY OF THE INVENTION

This document describes techniques for performing user scheduling for uplink transmission in a wireless communication system. In one aspect, scheduling may be performed for users, taking into account the excess of thermal noise (RoT) in a cell, which may increase capacity. In one design, the total load for a cell can be determined based on a RoT measurement. The internal cell load for users served by that cell can be determined based on uplink transmissions received from these users. The external load created by users of neighboring cells can be determined based on the total load and internal load on the cell. The target total cell load can be determined based on the target RoT of the cell. The available load for the cell can be determined based on the target total cell load and external load. For cell users, scheduling for uplink transmission based on available cell load can be performed.

In one design, users can be scheduled, one user at a time, based on their priorities. The user can be assigned a data rate based on the power headroom and the size of the user's queue. The user load can be determined based on the set data rate and other relevant information. The available load can be updated by subtracting the user load. For another user, you can plan in a similar way based on the updated available load.

Various aspects and features of the disclosure are described in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

1 shows a wireless communication system.

Figure 2 shows a graph of the normalized cell throughput in relation to RoT.

Figure 3 shows a block diagram of a device for calculating various loads.

Figure 4 shows a block diagram of an apparatus for performing user scheduling on an uplink.

5 shows a process for scheduling users in a cell.

Figure 6 shows the process of determining the external load.

7 shows a process for performing user scheduling based on available load.

FIG. 8 shows a process performed by a UE for uplink transmission.

FIG. 9 shows a block diagram of a UE, two Nodes B, and a network controller.

DETAILED DESCRIPTION

The techniques described herein can be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other systems. The terms “system” and “network” are often used interchangeably. A CDMA system can implement such radio technology as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Broadband CDMA (W-CDMA) and other CDMA options. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA system can implement such radio technology as advanced UTRA (E-UTRA), ultra-mobile wideband (UMB), IEEE 802.20, IEEE 802.16 (WiMAX), 802.11 (WiFi), Flash-OFDM®, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) is the upcoming release of UMTS that uses E-UTRA. UTRA, E-UTRA, UMTS, LTE, and GSM are described in documents from an organization called the 3rd Generation Partnership Project (3GPP). CDMA2000 and UMB are described in documents from an organization called 3rd Generation Partnership Project 2 (3GPP2). These various technologies and standards are known in the art. For clarity, some technology aspects are described below for UMTS, and UMTS terminology is used in a large number of descriptions below.

1 shows a wireless communication system 100, which may be a universal terrestrial radio access network (UTRAN) in a UMTS. System 100 includes several Nodes B 110. Node B is a fixed station that communicates with a UE and may be referred to as an evolved Node B (eNB), base station, access point, etc. Each Node B 110 provides communication coverage for a specific geographic area 102 and communicates with UEs located in the coverage area. The coverage area of Node B can be divided into several (for example, three) smaller zones, and each of these smaller zones can be served by the corresponding subsystem of Node B. Depending on the context of use of the term, the term "cell" may denote the smallest coverage area of Node B and / or Node B subsystem serving the coverage area. In the example shown in FIG. 1, Node B 110a serves cells A1, A2 and A3, Node B 110b serves cells B1, B2 and B3, and Node B 110c serves cells C1, C2 and C3.

The network controller 130 may connect to the Nodes B 110 and provide coordination and control of these Nodes B. The network controller 130 may be a single network entity or a combination of network entities.

UE 120 can be dispersed throughout the system, and each UE can be stationary or mobile. A UE may also be referred to as a mobile station, terminal, access terminal, subscriber unit, station, etc. A UE may be a cell phone, a personal digital assistant (PDA), a wireless device, a portable device, a wireless modem, a laptop computer, etc. A UE may communicate with a Node B by transmitting on the downlink and uplink. The downlink (or forward channel) refers to the communication link from the Node B to the UE, and the uplink (or reverse channel) refers to the communication link from the UE to the Node B. For clarity, only the uplink transmissions are shown in FIG. communications from UE 120 to Nodes B 110. In FIG. 1, a solid line with one arrow indicates transmission to a serving cell, and a dashed line with one arrow indicates transmission to a non-serving cell. In this document, the terms “UE” and “user” are used interchangeably.

3GPP Release 6 and later supports High Speed Uplink Packet Access (HSUPA), which is a set of channels and procedures that enable high speed uplink packet data. For HSUPA, and the user can send a message with scheduling information (SI) containing information about the queue length and power reserve of the user. This information can be translated into the maximum data rate supported by the user on the uplink. The scheduler can schedule the user for uplink transmission and can send the user permission on an E-DCH absolute resolution channel (E-AGCH) or on an E-DCH relative resolution channel (E-RGCH). A user may have an active set comprising a serving cell and zero or more non-serving cells. The serving cell may send (i) an absolute resolution to the E-AGCH to indicate the amount of transmit power that the user can use for uplink transmission, or (ii) a relative resolution on the E-RGCH to indicate a change from the current resolution, for example, increase or decrease current resolution by a certain amount. Each non-serving cell can track the user and can only send relative permissions to reduce the current resolution.

HSUPA supports uplink hybrid automatic retransmission (HARQ). For HARQ, a user can send a packet transmission to a serving cell and can send zero or more retransmissions of a packet until a confirmation (ACK) is received for the packet or the maximum number of retransmissions is sent or the packet is terminated for any reason. other reasons. In HSUPA, retransmission of the expected packet has a higher priority than the transmission of a new packet. An expected packet is a packet that was sent but decoded with an error.

As shown in FIG. 1, each cell may receive transmissions from users served by this cell, as well as transmissions from users not served by this cell. The total interference observed on each cell consists of (1) intra-cell interference from users within one cell and (2) inter-cell interference from users of other cells. Intra-cell interference and inter-cell interference have a big impact on performance and can be taken into account when planning users, as described below.

On the uplink of system 100, transmission from each user acts as a mutual interference to transmissions from other users. Thus, when uplink scheduling is performed for a new user, transmission from that user increases mutual interference to other users. The amount of interference caused by the new user may depend on various factors, such as the amount of transmit power used by the user, losses in the transmission path from the user to the cell, etc. To combat increased mutual interference, each remaining user can increase their transmit power, which, in turn, can increase the level of mutual interference on the cell. As more users are added, other active users may need to increase the power of their transmissions and the overall level of mutual interference on the cell may increase. At some point, users cannot be added. Thus, the system can be limited by mutual interference in the uplink.

2 shows a graph 210 of normalized cell throughput with respect to RoT for uplink. RoT is the ratio of total noise and interference to thermal noise in a cell. The normalized cell throughput is the total bandwidth of all users on the uplink, divided by the maximum total bandwidth. As shown in FIG. 2, cell throughput increases by a larger percentage at low RoT and asymptotically reaches maximum values at high RoT.

RoT is a fundamental measure of uplink load. RoT can be maintained below a certain level to avoid system instability. RoT may vary depending on the number of users for which uplink scheduling has been performed and the UE data rates for which scheduling has been performed.

In one aspect, scheduling for uplink transmission can be performed for users, taking into account RoT in a cell. In one design, RoT cells can be measured and used to determine the total load on the cell. The external load from users in neighboring cells can be determined based on the total load and intra-cell load from users served by the cell. The target total cell load can be determined based on the target RoT of the cell. The available load for the cell can be determined based on the target total load and the external load, and can be distributed to users in the cell. Thus, RoT can be used to determine both the external load and the available cell load. These various loads are described in detail below.

The ratio of the total energy per chip to the total noise, (E _c / N _t ) _i , for a given user i on a given cell can be expressed as:

Where

E _cp is the energy per chip for the pilot,

E _c is the total energy per chip for data, overhead and pilot,

N _t is the total noise and interference observed by user i,

O2P _i (or Gain _overhead ) is the ratio of overhead to pilot for user i, and

T2P _i is the ratio of traffic to pilot for user i.

The ratio of the energy of the pilot signals per chip to the total noise, (E _cp / N _t ) _i , for user i can be estimated based on the pilot signal transmitted by user i over the uplink. User i may transmit overhead or signaling at a power level determined by 02P _i , and may transmit data at a power level determined by T2P _i , wherein 02P _i is the ratio of the signaling power level to the pilot power level, and T2P _i is the ratio data power level to pilot power level. The pilot power level can be adjusted by power control to achieve the desired performance level, for example, target packet error rate (PER). The relationships O2P _i and T2P _i may be known in advance or may be determined for user i. Can then be calculated for user _{i (E c / N t)} i based on the evaluation of (E _cp / N _{t) i} and a known O2P _i and T2P _i.

The load of user i can be expressed as:

Where

(E _c ) _i is the total energy per unit for user i,

I ₀ is the total noise and interference observed by the hundredth, and

L _i is the load of user i.

The total noise and mutual interference, I ₀ observed by the hundredth, can be expressed as follows:

where N ₀ is the thermal noise observed by the hundredth.

The total noise and interference (N _t ) _i observed by the user can be expressed as:

The second equality in equation (2) can be obtained by dividing (E _c ) _i by (N _t ) _i , dividing I ₀ by (N _t ) _i and replacing I ₀ by (N _t ) _i + (E _c ) _i from the equation (four).

The uplink transmission from user i may be processed by a Rake receiver or an equalizer of a cell. In the case of a Rake receiver, one or more channels of the Rake receiver can be assigned to user i, and each channel of the Rake receiver can process a different signal path for user i. In this case (E _cp / N _t ) _i can be estimated on each of the assigned Rake receiver channels, the load for each of the Rake receiver channels can be calculated based on the estimate (E _cp / N _t ) _I , as shown in equation ( 2), and the load for all the assigned channels of the Rake receiver can be summed to obtain the load of user i. For an equalizer, the load of user i can be calculated based on the load equation defined for the equalizer.

The load of all users served by the hundredth, L _in-cell , can be expressed as:

where Cell is the set of users served by the hundredth. L _{in-cell is} also called intra _-cell loading.

The load of all users not serviced by the cell, but having a cell in their active sets, L _{ns, As} , can be expressed as:

where ActiveSet is the set of all users who have a cell in their active sets. L _{ns, As} can also be designated as a load of maintenance-free active lists. An unattended user is a user who is not served by a cell, but has a cell in its active set.

A cell may have direct control over the loads of users discussed by this cell, for example, using absolute and relative permissions for these users. A cell may have indirect control over the load of unattended users, for example, by decreasing relative permissions for these users. L _{ns, As} can be calculated separately to determine whether or not to send relative permissions to these unattended users.

The total cell load, L _{total_cell} , can be expressed as:

where L _out is the load of users in other cells and not having a cell in their active sets. L _out can also be referred to as external load.

The total cell load can be expressed through RoT as follows:

RoT can be measured as described below. Then, based on the measured RoT, it is possible to calculate L _{total_cell} , as shown in equation (8). Then you can calculate the external load as:

Users can transmit a pilot on the uplink in each slot with a duration of 0.667 milliseconds (ms). L _in-cell , L _{ns, AS} and L _out can be calculated in each slot, as described above. These quantities can be noisy and can be filtered by filters with an infinite impulse response (IIR) as follows:

,

и

- это отфильтрованные для слота n значения, и T_in-cell, T_ns,AS и T_out - это временные константы для L_in-cell, L_ns,AS и L_out соответственно.where L _in-cell (n), L _{ns, AS} (n) and L _out (n) are the values calculated for slot n,

,

and

are the values filtered for slot n, and T _in-cell , T _{ns, AS,} and T _out are time constants for L _in-cell , L _{ns, AS,} and L _out, respectively.

,

и

. RoT соты можно измерить в блоке 310, как описано ниже. Суммарную нагрузку соты L_{total_cell} можно вычислить на основании измеренного RoT в блоке 312, например, как показано в уравнении (8).Figure 3 shows a block diagram of the design of the device 300 for calculating

,

and

. RoT cells can be measured at block 310, as described below. The total cell load L _{total_cell} can be calculated based on the measured RoT in block 312, for example, as shown in equation (8).

For each user who has cells in his active set, O2P _{i of the} user can be defined in block 320, T2P _{i of the} user can be defined in block 322 and (E _cp / N _t ) _{i of the} user can be determined in block 324. (E _c / N _t ) _i each user can be calculated based on (E _cp / N _t ) _i , O2P _i and T2P _i in block 326, for example, as shown in equation (1). The load of each user can be calculated based on (E _c / N _t ) _i in block 328, for example, as shown in equation (2).

,

и

можно использовать для выполнения планирования, как описано ниже.Each user served by the cell can be transferred to block 332, and each user who has a cell in the active set but not served by the cell can be transferred to block 334. The intra _-cell load L _in-cell can be calculated in block 332, accumulating the load all users served by the hundredth, for example, as shown in equation (5). The maintenance-free load of the active set L _{ns, AS} can be calculated in block 334, accumulating the load of all maintenance-free users, for example, as shown in equation (6). The external load L _out can be calculated in block 330 by subtracting the intra _-cell load L _in-cell and the non-serving load of the active set L _{ns, AS} from the total load of the cell L _{total_cell} , for example, as shown in equation (9). The external load L _out can be filtered in block 340, for example, as shown in equation (12). The intra _-cell load L _in-cell can be filtered in block 342, for example, as shown in equation (10). The non-serving load of the active set L _{ns, AS} can be filtered in block 344, for example, as shown in equation (11). Filtered loads and

,

and

can be used to carry out planning as described below.

In HSUPA, users can schedule at each transmission time interval (TTI), which can be 2 ms or 10 ms. For users, scheduling for uplink transmission can be performed so that the RoT is at the target level, as shown in FIG. 2. This target RoT can be converted to the target total load as follows:

where L _{total, target} is the target total load for the cell.

The available load for the cell, L _{avail_cell} , can be expressed as:

и

- это текущие отфильтрованные значения L_out и L_ns,AS соответственно.Where

and

are the current filtered values of L _out and L _{ns, AS,} respectively.

For users in a cell, scheduling based on available load can be performed in various ways. In one design, the available load can be distributed to different classes or types of gears in the following order:

1. Transmissions on dedicated channels assigned to users,

2. Retransmission of pending data using HARQ,

3. Transmissions autonomously sent by users who do not require scheduling, and

4. Transfer of new data.

The user can be assigned one or more dedicated channels for data transmission, signaling, pilot signals, etc. The user can also be allowed to transmit data at any time up to a predetermined autonomous data rate without the need for scheduling. This autonomous data rate can be configured in advance and can be used to send data sensitive to delays (e.g. voice data) and / or small amounts of data. Offline transmission of such data can reduce overhead planning and delays. The user may also have a pending packet that has not been correctly decoded by the cell and may require sending a retransmission of the packet.

The load of dedicated channels for all users served by the cell can be determined based on (E _cp / N _t ) _i and O2P _i and T2P _{i of} each user. Users with pending packets can be identified, and the burden of retransmission of pending packets from these users can be determined. You can also determine the load of offline transmissions from users. Then the load available for planning, L _{avail_sched} , can be expressed as:

Where

L _DPCH is the load of transmissions on dedicated channels,

L _retran is the load of retransmissions of pending packets, and

L _autonomous is the load of autonomous gears.

The available load L _{avail_sched} can be distributed to users requesting uplink transmission based on various scheduling schemes. In one of the planning schemes, requesting users can be prioritized based on various factors, such as the data rates they support, average throughput, quality of service (QoS) requirements, etc. In one design, user priority can be expressed as:

Where

R _{supported, i} is the maximum data rate for user i,

TP _i is the average throughput for user i, and

Priority _i is the priority of user i.

Users can also prioritize in a different way or based on other parameters. In any case, users can be sorted based on their priorities. Then the available load L _{avail_sched} can be distributed to the sorted users, one at a time, starting with the user with the highest priority.

In order to plan first and foremost for the user with the highest priority, based on the information about the queue length and the power reserve of the user, the maximum supported data rate R _{supported, i} can be calculated. For the user, the data rate R _{sched, i} can be selected based on the maximum supported data rate R _{supported, i} and the available load L _{avail_sched} . The planned data rate is equal to or less than the maximum supported data rate, and is further limited by the available load. The load of the user for which scheduling was performed, L _{sched, i} , can be calculated based on the planned data rate R _{sched, i} and (E _cp / N _t ) _{i of the} user. The various supported data rates may be associated with different values of E _c / N _t and thus different values of T2P. The T2P values for the planned data rate can be determined, for example, from a table view. Then, based on the value of T2P for the planned data rate and (E _cp / N _t ) _{i of the} user, it is possible to determine the load of the user for whom the planning was performed, for example, as shown in equations (1) and (2). The available load L _{avail_sched} can then be reduced by the load L _{sched, i of the} user for whom scheduling was performed. For the next highest priority user, scheduling can be done in a similar way. The process may be repeated until scheduling has been completed for all requesting users, or until the available load L _{avail_sched} becomes zero or too small.

и отфильтрованную необслуживающую нагрузку активного набора

из целевой суммарной нагрузки L_{total_target} для получения доступной для соты нагрузки L_{avail_cell}, например, как показано в уравнении (14). Нагрузку L_DPCH передач по выделенным каналам можно вычислить в блоке 414. Нагрузку L_retran повторных передач ожидающих пакетов можно вычислить в блоке 416. Нагрузку L_autonomous автономных передач можно вычислить в блоке 418. Сумматор 420 может вычесть нагрузку выделенных каналов L_DPCH, нагрузку повторных передач L_retran и нагрузку автономных передач L_autonomous из доступной соте нагрузки L_{avail_cell} для получения доступной нагрузки L_{avail_sched} для выполнения планирования пользователей.FIG. 4 shows a block diagram of a design of an apparatus 400 for scheduling uplink users. An adder 410 can subtract the filtered external load

and filtered non-maintenance active set load

from the target total load L _{total_target} to obtain the available load L _{avail_cell} for the cell, for example, as shown in equation (14). The load L _{DPCH of} transmissions on dedicated channels can be calculated in block 414. The load L _{retran of} retransmissions of pending packets can be calculated in block 416. The load L of _autonomous transmissions of autonomous transmissions can be calculated in block 418. Adder 420 can subtract the load of the allocated channels L _DPCH , the load of retransmissions L _retran and the load of the autonomous transmissions L _autonomous from the available load cell L _{avail_cell} to obtain the available load L _{avail_sched} for user scheduling.

In block 422, based on the queue size, power headroom, and (E _cp / N _t ) _i user, the maximum supported data rate R _{supported, i} for each user requesting uplink transmission can be calculated. At any time when scheduling is performed on a user, at block 424, the average throughput of each user can be updated. The priority of each user can be determined in block 426, for example, as shown in equation (16). Requesting users can be sorted in block 428 based on their priorities. Then, for each user who needs to be scheduling, in block 430, it is possible to determine the planned data rate R _{sched, i} based on the maximum user supported data rate and currently available load from selector 434. The user load L _{sched, i} , in respect of which scheduling is performed, it can be determined in block 432 based on the planned data rate and other relevant information. The selector 434 provides the available load L _{avail_sched} from the adder 420 for the first user and provides an updated available load from the adder 436 for each subsequent user. Adder 436 subtracts the user load L _{sched, l} , for which scheduling was performed, from the available load L _{avail_sched} to update the available load for the remaining users.

A cell may reduce data rates for non-serving users having a cell in its active set but not being served by the cell. In one design, relative permissions to reduce data rates of unattended users can be generated in block 412 if the following conditions are true:

where L _{thresh, As} is the threshold, and K _{ns, As} is the coefficient used to reduce the data rates of unattended users. Data rates of unattended users can also be reduced based on other conditions and / or parameters.

In the design described above, the non-maintenance load of active sets L _{ns, As} can be determined separately and used to send relative permissions to non-maintenance users. Both L _{ns, As} , and L _out can be subtracted from the total target load L _{total_target} to obtain the available load of the cell L _{avail cell} , for example, as shown in equation (14). L _{ns, AS} and L _out can be considered as the total load of users not served by the hundredth.

In another design, the intra _-cell load L _in-cell can be determined, for example, as shown in equation (5), but the non-maintenance load of the active sets L _{ns, AS is} not determined. Then the external load Ľ _out can be calculated as follows:

. Затем можно определить доступную нагрузку соты L_{avail_cell} на основании L_{total_target} и

следующим образом:Ľ _out includes both the non-maintenance load of the active set L _{ns, AS} and the external load L _out . Ľ _out can be filtered (e.g. with an IIR filter) to obtain

. You can then determine the available cell load L _{avail_cell} based on L _{total_target} and

in the following way:

Then, L _{avail_cell} can be distributed to users as described above.

In another scheduling scheme, each requesting user (or each user that was scheduled in the previous TTI) can be assigned a reserved data rate that may be lower than the maximum user-supported data rate. In one design, the reserved data rate for each user may be one data rate lower than the last planned data rate for that user. The load of reserved data rates for all users can be calculated and subtracted from the available load L _{avail_sched} . Then, the remaining available load can be distributed to requesting users, for example, as described above. This scheduling scheme can ensure that at least a portion of their maximum supported data rate is allocated to requesting users (or to users previously scheduled).

Other scheduling schemes can also be used to distribute the available load L _{avail_sched to} requesting users. For example, the available load can be distributed according to the cyclic algorithm scheme, proportional fairness scheme based on the reported power reserve, proportional fairness scheme based on the reported power reserve and power control, proportional fairness scheme based on the reported power reserve and signal quality received on the uplink and etc.

RoT cells can be measured to calculate the total cell load L _{total_cell} . RoT can be expressed as:

The total noise and interference I ₀ can be easily measured as the total received hundredth power. Thermal noise N ₀ can be measured in several ways. In one design, N ₀ can be measured during a silence interval during which no user transmits on the uplink. Then N ₀ can be measured as the total received hundredth power during the silence interval. In another design, the total received power in the sideband between two WCDMA carriers can be measured and used to estimate N ₀ . For example, samples prior to the pulse shaping filter in a cell can be converted by the Fast Fourier Transform (FFT) to obtain the power spectral density of both the main band and the side band. Then, N ₀ can be determined based on a portion of the power spectral density for the sideband. N ₀ can also be measured by other methods. In any case, the RoT of the cell can be calculated based on measured I ₀ and measured N ₀ .

The planning technologies described in this document can provide certain benefits. First, a more accurate available cell load L _{avail_cell} can be obtained by determining the external load L _out based on the RoT measurement. This may allow the cell to work closer to the total target load L _{total_target} , which may increase capacity. The more accurate available cell load L _{avail_cell} may also allow the cell to operate at a higher total target load L _{total_target} , while providing stability.

5 shows a design of a process 500 for scheduling users in a cell. Process 500 may be performed by a scheduler, which may reside in Node B 110 or network controller 130. The external load from users in neighboring cells and unattended cells may be determined (block 512). The external load may correspond to L _out in equation (9) or Ľ _out in equation (18). The available load for the cell can be determined based on the target total load for the cell and the external load (block 514). The target total load for the cell can be determined based on the target RoT, for example, as shown in equation (13). The external load can be filtered to obtain a filtered external load, and the available load can be determined based on the total target load and the filtered external load. For users of the cell, scheduling for uplink transmission may be performed based on the available load for the cell (block 516).

Figure 6 shows the design of block 512 of figure 5 for determining the external load. The total load for the cell can be determined based on the RoT measurement (block 612). The intra-cell load for users served by the cell may be determined based on uplink transmissions received from these users (block 614). You can also determine the non-serving load of the active set for maintenance-free users who are not served by the cell but have a cell in their active sets (block 616). You can then determine the external load based on the total load, the intra-cell load, and possibly the non-serving load of the active set, for example, as shown in equation (14) or (19) (block 618).

In one design of block 612, a RoT measurement can be obtained based on the measurement of thermal noise and the measurement of the total received power for the cell. The thermal noise measurement can be obtained based on the measurement of the signal for the sideband between the carriers, the measurement of the signal performed during the silence interval without users transmitting on the uplink, etc.

In one design of block 614, the load of each user served by the hundredth can be determined based on the ratio of the total energy per chip to the total noise of the user, for example, as shown in equation (2). The ratio of the total energy per chip to the total noise for the user can be determined based on the ratio of the energy of the pilot signals per chip to the total noise, the ratio of traffic to pilot and, possibly, the ratio of overhead to pilot for the user, for example, shown in equation (1). The intra-cell load can be determined based on the loads of all users served by the cell, for example, as shown in equation (5).

In one design of block 516 of FIG. 5, available load can be first allocated to transmissions on dedicated channels, assigned to users, retransmissions of pending packets, autonomous transmissions by users and / or other types of transmissions before new transmissions. You can determine the load from the allocated channels and subtract it from the available load. You can determine the load from retransmissions and subtract it from the available load. You can determine the load from autonomous gears and subtract it from the available load. The updated available load can then be distributed to users in the cell.

7 shows the design of a process 700 for performing scheduling based on available load. Process 700 may be used for block 516 of FIG. 5. The priorities of users with respect to which scheduling is to be performed in a cell can be determined, for example, as shown in equation (16), or based on some other scheme (block 712). Users can be sorted based on their priorities (block 714). The available load can then be distributed to sorted users, one user at a time. The user with the highest priority may be selected first (block 716). The user can be assigned a data rate, for example, based on the power reserve and the size of the user's queue, available load, etc. (block 718). The user load can be determined based on the assigned data rate and other relevant information (block 720). Then, the available load can be updated by subtracting the user load (block 722). If there is still available load and scheduling has not been completed for all users, as determined in block 724, the process returns to block 716 to schedule the next user with the highest priority. Otherwise, the process ends. Also, for maintenance-free users, relative permissions can be generated based on the non-serving active set load and the intra-cell load, for example, as shown in equation (17).

In another design, users can assign reserved data rates. The load from the backup data rates can be determined and subtracted from the available load. Then the updated available load can be distributed to users.

FIG. 8 shows a design of a process 800 performed by a UE. The UE may send a request (eg, scheduling execution information message) for uplink transmission to the cell (block 812). The UE may receive permission for uplink transmission from the cell, the resolution being determined based on the available load for the cell (block 814). The available load for the cell can be determined based on the target total load for the cell and the external load from users outside the cell. The UE may send an uplink transmission in accordance with the resolution (block 816).

The UE may send at least one dedicated channel to the cell. The available load can be further determined based on the load from the dedicated channels of all users of the cell. The UE may send retransmissions of pending packets to the cell. The available load can be further determined based on the load from retransmissions of all users. The UE may autonomously send transmissions to the cell. The available load can be further determined based on the load from the autonomous transmissions of all users of the cell.

FIG. 9 shows a block diagram of a structure of UE 120, which may be one of the UEs in FIG. 1. On the uplink, encoder 912 may receive data and signaling (eg, requests or SI messages) that the UE 120 should send on the uplink. Encoder 912 may process (e.g., format, encode, interleave) data and signaling. A modulator (Mod) 914 may further process (eg, modulate, transmit over a channel, encrypt) encoded data and signaling and provide output chips. The transmitter (TMTR) 922 can specify the state (for example, convert to analog, filter, amplify, increase the frequency) of the output elementary packets and generate a signal on the uplink, which can be transmitted by the antenna 924 to one or more Nodes B.

On the downlink, the antenna 924 can receive downlink signals transmitted by one or more Nodes B. The receiver (RCVR) 926 can specify the state (e.g., filter, amplify, lower the frequency and digitize) of the signal received from the antenna 924 and provide samples. Demodulator (Demod) 916 can process (eg, decrypt, channel and demodulate) samples and provide symbol estimates. Decoder 918 may further process (eg, reconstruct and decode) the symbol estimates and provide decoded data and signaling (eg, absolute and relative resolutions) sent to UE 120. Encoder 912, modulator 914, demodulator 916, and decoder 918 may be implemented by a processor 910 modems. These devices may perform processing in accordance with the radio technology (eg, W-CDMA) used in the wireless system.

The controller / processor 930 may direct the operation of various devices to the UE 120. The controller / processor 930 may provide the execution of the process 800 of FIG. 8 and / or other processes for the technologies described herein. Memory 932 may store program codes and data for UE 120.

FIG. 9 also shows a block diagram of the design of Nodes B 110a and 110b of FIG. 1. Node B 110a can support a serving cell for UE 120, and Node B 100b can support a neighboring cell or non-serving cell in the active set of UE 120. At each Node B 110, transmitter / receiver 938 can communicate with UE 120 and other UEs. Controller / processor 940 may perform various functions for communicating with multiple UEs. For uplink transmission, an uplink signal from UE 120 may be received (and may be set to a state by receiver 938) and further processed by a controller / processor 940 to recover data and signaling sent on the uplink of the UE. For downlink transmission, data and signaling can be processed by controller / processor 940 and can be set by transmitter 938 to generate a downlink signal that can be transmitted to multiple UEs. A memory 942 may store program codes and data for the Node B. Communication device 944 (Comm) may communicate with the network controller 130.

9 also shows a block diagram of the design of the network controller 130. On the network controller 130, the controller / processor 950 may perform various functions to support communication services for multiple UEs. Memory 952 may store program codes and data for network controller 130. Communications device 954 may communicate with Nodes B 110.

Performing user scheduling for the serving cell may be performed by Node B 110a, a network controller 130, or some other entity. The controller / processor 940 or 950 may implement the process 500 of FIG. 5, the process 512 of FIG. 6, the process 700 of FIG. 7, and / or other processes for the technologies described herein. Also, the controller / processor 940 or 950 may execute block 300 of FIG. 3 or block 400 of FIG. 4.

Specialists in this field understand that information and signals can be represented by various technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols and chips used throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

Additionally, those skilled in the art will recognize that the various illustrative logical blocks, modules, circuits, and algorithm steps described herein in conjunction with the disclosure of the invention can be implemented with electronic hardware, computer software, or a combination of both. In order to clearly illustrate this interchangeability of software and hardware, various illustrative components, blocks, modules, circuits, and steps are typically described above in terms of their functionality. Whether this functionality is implemented as hardware or software depends on the particular application and design constraints imposed on the entire system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the disclosure.

The various illustrative logical blocks, modules, and circuits described herein in conjunction with the disclosure may be implemented or performed using a general purpose processor, digital signal processing processor (DSP), application specific integrated circuit (ASIC), reprogrammable gate array (FPGA), or other programmable logic device, discrete component circuitry or transistor logic, discrete hardware components, or any combination thereof to perform the functions described in this document ente. A general purpose processor may be a microprocessor, but, alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices, for example, a combination of a DPS and a microprocessor, a plurality of microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration.

The steps of a method or algorithm described herein in conjunction with the disclosure of the invention can be implemented directly in hardware, a software module executed by a processor, or a combination thereof. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. A typical storage medium is connected to the processor so that the processor can read information from and write information to the storage medium. Alternatively, the storage medium may be integrated into the processor. The processor and storage media may reside in an ASIC. ASIC may reside in a user terminal. Alternatively, the processor and the storage medium may reside as discrete components in a user terminal.

In one or more typical designs, the described functions may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions can be stored on or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any media that can transfer a computer program from one place to another. The storage medium may be any available medium that can be accessed by a general or special purpose computer. By way of non-limiting example, such a computer-readable medium may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk drive, a magnetic disk drive or other magnetic storage device, or any other medium that can be used to transfer or store desired programs or program codes in the form of instructions or data structures and which can be accessed by a general or special purpose computer or a general or special purpose processor. As well as any connection to which the term computer-readable medium can legitimately be attributed. For example, if the software is transferred from a website, server or other remote source using a coaxial cable, fiber optic cable, twisted pair cable, digital subscriber line or wireless technologies such as infrared, radio and microwave, then the coaxial cable, fiber optic cable, twisted pair, digital subscriber line or wireless technologies such as infrared, radio and microwave are part of the definition of the medium. A disc, as used herein, includes a compact disc (CD), a laser disc, an optical disc, a universal digital disc (DVD), a floppy disc, and a blu-ray disc, where discs typically reproduce data optically when using lasers or using magnetic fields. Combinations of the above should also be included within the scope of computer-readable media.

The previous description of the disclosure is provided so that those skilled in the art can make or use the invention. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the scope of this disclosure. Thus, the disclosure is not intended to be limited by the examples and constructions described herein, but should be construed in a broad scope consistent with the principles and new features described herein.

Claims (42)

1. A wireless communication device comprising
a processor configured to determine an external load from users in neighboring cells, determine an available load for the cell based on the target total load for the cell and the external load, and perform user scheduling in the cell for uplink transmission based on the available load for the cell; and
memory connected to the processor, containing instructions for the processor to perform the above capabilities. 2. The device according to claim 1, in which the processor is configured to determine the total load per cell based on the measurement of excess over thermal noise (RoT), determine the intra-cell load for users served by the cell, and to determine the external load based on the total load and intra-cell load. 3. The device according to claim 2, in which the processor is configured to determine the load of the non-serving active set for maintenance-free users, maintenance-free cell, but having a cell in the active sets of users, and determining the external load additionally based on the load of the maintenance-free active set. 4. The device according to claim 2, in which the processor is configured to filter the external load to obtain a filtered external load and determine the available load based on the target total load and the filtered external load. 5. The device according to claim 2, in which the processor is configured to determine the load of each user served by the cell, and determine the intra-cell load based on the loads of all users served by the cell. 6. The device according to claim 5, in which the processor is configured to determine the ratio of the energy of the pilot signal per chip to the total noise of each user served by the cell, to determine the ratio of the total energy per chip to the total noise of each user based on the ratio of the energy of the pilot a signal per chip to the total noise, and at least one of the traffic to pilot ratio and the overhead to pilot ratio for the user, and determining each load th user on the basis of the total energy ratio per chip to the total noise for the user. 7. The device according to claim 3, in which the processor is configured to generate relative permissions for non-serving users based on the load of the non-serving active set and the intra-cell load. 8. The device according to claim 2, in which the processor is configured to obtain a measurement of thermal noise, obtain a measurement of the total received power and obtain a RoT measurement based on a measurement of thermal noise and measure the total received power. 9. The device of claim 8, in which the processor is configured to obtain a measurement of thermal noise based on the measurement of the signal for the sideband between the carriers. 10. The device according to claim 8, in which the processor is configured to obtain a measurement of thermal noise based on a signal measurement made during a period of silence when none of the users transmits on the uplink. 11. The device according to claim 1, in which the processor is configured to determine the target total load for the cell based on the target excess of thermal noise (RoT). 12. The device according to claim 1, in which the processor is configured to distribute the available load on the dedicated channels assigned to users prior to new transmissions, determine the load from the dedicated channels and update the available load by subtracting the load from the dedicated channels. 13. The device according to claim 1, in which the processor is configured to distribute the available load on retransmissions to new transmissions, determine the load from retransmissions and update the available load by subtracting the load from retransmissions. 14. The device according to claim 1, in which the processor is configured to distribute the available load on offline transmissions by users to new transmissions, determine the load from offline transmissions, and update the available load by subtracting the load from offline transmissions. 15. The device according to claim 1, in which the processor is configured to determine the priorities of users for which the cell should be scheduled, sort users based on priorities and the distribution of available load on the sorted users, one user at a time, starting with the user with the highest priority. 16. The device according to claim 1, in which the processor is configured to assign the user in relation to which the scheduling is performed, the data transfer rate, determine the user load based on the assigned data rate and update the available load by subtracting the user load. 17. The device according to clause 16, in which the processor is configured to determine the data rate assigned to the user based on the power reserve and the size of the user queue. 18. The device according to claim 1, in which the processor is configured to assign reserved data rates to users in respect of which the cell must plan, determine the load from the reserved data rates, update the available load by subtracting the load from the reserved data rates and distributing the updated available load to users for which planning must be performed in the cell. 19. The device according to claim 1, in which the processor is configured to perform user scheduling in a cell for uplink transmission with high speed uplink packet access (HSUPA). 20. A wireless communication method, comprising the steps of: determining an external load from users in neighboring cells;
determining a load available for the cell based on the target total load for the cell and the external load; and
scheduling users in the cell for uplink transmission based on the load available for the cell. 21. The method according to claim 20, in which the determination of the external load comprises the steps of
determining the total load for the cell based on the measurement of the excess over thermal noise (RoT),
determining an intra-cell load for users served by the hundredth, and
determine the external load based on the total load and intra-cell load. 22. The method of claim 21, wherein the step of determining the external load further comprises the steps of:
determining a non-serving active set load for users who are not being served by a cell but having a cell in active user sets, and
determine the external load further based on the load of the non-serving active set. 23. The method according to item 21, in which the stage at which determine the intra-cell load, comprises the steps of
determining the load of each user served by the cell, and determining the intra-cell load based on the loads of all users served by the cell. 24. The method according to item 21, further comprising stages, in which
get a measurement of thermal noise;
receive a measurement of the total received power; and
receive a RoT measurement based on a measurement of thermal noise and a measurement of the total received power. 25. The method according to claim 20, in which the step of scheduling users in the cell, comprises the steps of
assign a data rate to the user in relation to whom the planning is performed,
determining a user load based on the assigned data rate, and
update the available load by subtracting the user load. 26. A wireless communication device comprising: means for determining an external load from users in neighboring cells;
means for determining a load available for the cell based on the target total load for the cell and external load; and
means for performing user scheduling in the cell for uplink transmission based on the load available for the cell. 27. The device according to p. 26, in which the means for determining the external load contains means for determining the total load on the cell based on the measurement of excess over thermal noise (RoT),
means for determining an intra-cell load for users served by a cell, and
means for determining the external load based on the total load and the intra-cell load. 28. The device according to item 27, in which the means for determining the external load further comprises
means for determining the load of a non-serving active set for users who are not served by a cell but having a cell in active user sets, and
means for determining an external load further based on the load of the non-serving active set. 29. The device according to item 27, in which the means for determining the intra-cell load contains
means for determining the load of each user served by the hundredth, and
means for determining the intra-cell load based on the loads of all users served by the cell. 30. The device according to item 27, further containing a means for obtaining a measurement of thermal noise;
means for obtaining a measurement of the total received power; and
means for obtaining a RoT measurement based on a thermal noise measurement and a measurement of the total received power. 31. The apparatus of claim 26, wherein the means for performing user scheduling in a cell comprises means for assigning a data rate to a user in respect of which scheduling is performed,
means for determining a user load based on the assigned data rate, and
means for updating the available load by subtracting the user load. 32. Computer-readable media containing
code that causes the computer to determine the external load from users in neighboring cells;
code that causes the computer to determine the load available for the cell based on the target total load and external load; and
code that causes the computer to schedule users in the cell for uplink transmission based on the load available for the cell. 33. The computer-readable medium of claim 32, further comprising
code that causes the computer to determine the total load for the cell based on the measurement of the excess over thermal noise (RoT);
code causing the computer to determine the intra-cell load for users served by the cell; and
code that causes the computer to determine the external load based on the total load and the intra-cell load. 34. The computer-readable medium of claim 32, further comprising a code causing the computer to assign a data rate to the user for whom scheduling is being performed;
code that forces the computer to determine the user load based on the assigned data rate; and
code that forces the computer to update the available load by subtracting the user load. 35. A wireless communication device comprising
a processor configured to send an uplink transmission request to the cell, receive permission for uplink transmission from the cell and send uplink transmission in accordance with the resolution, the resolution being determined based on the available load for the cell, and the available the load is determined based on the target total load for the cell and the external load from users not in the cell; and
memory connected to the processor, containing instructions for the processor to perform the above capabilities. 36. The device according to clause 35, in which the processor is configured to send at least one dedicated channel to the cell, and in which the available load is additionally determined based on the load from the dedicated user channels in the cell. 37. The device according to clause 35, in which the processor is configured to send retransmission of the expected packet to the cell, and moreover, the available load is determined additionally based on the load from retransmissions of users in the cell. 38. The device according to clause 35, in which the processor is configured to autonomously send the transmission to the cell without scheduling, and moreover, the available load is determined additionally based on the load from the offline transmissions of users in the cell. 39. A wireless communication method, comprising the steps of sending an uplink transmission request to a cell;
receiving a permission from the cell for uplink transmission, the resolution being determined based on the available load for the cell, the available load being determined based on the target total load for the cell and the external load from users not in the cell; and
send transmission on the uplink in accordance with the resolution. 40. The method according to § 39, further containing a stage on which
send at least one dedicated channel to the cell, and the available load is further determined based on the load from the dedicated user channels in the cell. 41. The method according to § 39, further containing a stage on which
send a retransmission of the pending packet to the cell, and the available load is further determined based on the load from the retransmissions of users in the cell. 42. The method according to § 39, further containing a stage on which
autonomously send a transmission to the cell without scheduling, and moreover, the available load is determined additionally based on the load from the autonomous transmissions of users in the cell.

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