CN108702174B

CN108702174B - Method and apparatus for communication

Info

Publication number: CN108702174B
Application number: CN201780013212.5A
Authority: CN
Inventors: 桂建卿; 郭君玄; 苏昭诚
Original assignee: MediaTek Inc
Current assignee: MediaTek Inc
Priority date: 2016-10-03
Filing date: 2017-06-20
Publication date: 2020-12-11
Anticipated expiration: 2037-06-20
Also published as: BR112019006513A2; WO2018064895A1; EP3494643A1; CN108702174A; TW201815205A; EP3494643A4

Abstract

Some aspects of the invention provide an apparatus comprising baseband processing circuitry and transmit circuitry. The baseband processing circuit is to encode a reference signal based on a particular sequence to generate a digital stream, wherein the particular sequence has a non-0 value at a selected position and a number of non-0 value position overlaps between the particular sequence and a shifted copy of the particular sequence is less than a threshold. The transmit circuit is operable to transmit a wireless signal in response to the digital stream. By using the present invention, synchronization and/or device identification can be better performed.

Description

Method and apparatus for communication

Cross-referencing

The present application claims 2016, filed 10/3/2016, U.S. provisional application 62/403,220 entitled "Synchronization Signal Design based on Pulse Position Modulation"; U.S. provisional application 62/404,807 entitled "Synchronization Signal Design based on Pulse Position Modulation", filed 2016, 10, 6, 2016; and us patent application 15/616,277 filed on 7.6.2017. And the above application is incorporated by reference.

Technical Field

The present invention relates to wireless communications, and more particularly, to a method and apparatus for synchronization.

Background

The background description provided herein is intended to generally present the context of the invention. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

In a wireless communication network, an electronic device may transmit one or more reference signals for synchronization and/or device identification (device identification). In an example, a base station broadcasts a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). From the PSS and SSS, a User Equipment (UE) may obtain timing information (timing information), frequency information, and identification of the base station.

Disclosure of Invention

Some aspects of the invention provide an apparatus comprising baseband processing circuitry and transmit circuitry. The baseband processing circuit is to encode a reference signal based on a particular sequence to generate a digital stream, wherein the particular sequence has a non-0 value at a selected position and a number of non-0 value position overlaps between the particular sequence and a shifted copy of the particular sequence is less than a threshold. The transmit circuit is operable to transmit a wireless signal in response to the digital stream.

In an example, the baseband processing circuit is configured to encode one or more reference signals for synchronization and/or device identification based on the specific sequence.

According to an aspect of the invention, the baseband processing circuitry is adapted to encode the reference signal in at least one of the time domain, the frequency domain or the time-frequency domain based on the specific sequence. The non-0 value may be constant, phase modulated, or amplitude modulated.

In an embodiment, the baseband processing circuitry is configured to encode the reference signal in the frequency domain based on the particular sequence, wherein the non-0 value is phase modulated to minimize a peak-to-average power ratio in the time domain. In an example, the baseband processing circuit is configured to encode the reference signal in a frequency domain based on the particular sequence, wherein a non-0 value is phase modulated according to binary phase shift keying.

In an embodiment the apparatus comprises sequence providing circuitry for providing said specific sequence to said baseband processing circuitry. In an example, the sequence providing circuit includes a memory to store the specific sequence. In another example, the sequence providing circuit includes a sequence generator circuit to generate the particular sequence. In another example, the sequence providing circuit includes an interface circuit to receive the specific sequence from an external source outside the apparatus.

Some aspects of the invention provide a method for communication, comprising: receiving a particular sequence having a non-0 value at a selected position, wherein a number of non-0 value position overlaps between the particular sequence and a shifted copy of the particular sequence is less than a threshold; encoding a reference signal based on a specific sequence to generate a digital stream; and transmitting a wireless signal in response to the digital stream.

By using the present invention, synchronization and/or device identification can be better performed.

Drawings

Some embodiments of the invention will now be described in detail, by way of example, with reference to the accompanying drawings. Wherein like numbers represent like elements. Wherein:

fig. 1 is a block diagram of an exemplary communication system 100 in accordance with an embodiment of the present invention.

Fig. 2 is a flow diagram of a process 200 according to an embodiment of the invention.

Fig. 3 is a diagram illustrating an example of an LDPB sequence according to an embodiment of the invention.

Fig. 4 is a diagram illustrating an LDPB sequence employed in different domains according to an embodiment of the present invention.

Detailed Description

Fig. 1 is a block diagram of an exemplary communication system 100 in accordance with an embodiment of the present invention. The communication system 100 includes a plurality of electronic devices, such as a first electronic device 110, a second electronic device 160, and the like, that communicate using wireless signals. At least one electronic device in the communication system employs a specific type of sequence for synchronization and/or device identification. Wherein a particular type of sequence is referred to as a Low Density Power Boost (LDPB) sequence.

The communication System 100 may be any suitable Wireless communication System using a suitable Wireless communication technology, such as a second generation (2G) Mobile Network technology, a third generation (3G) Mobile Network technology, a fourth generation (4G) Mobile Network technology, a fifth generation (5G) Mobile communication technology, a Global System for Mobile communication (GSM), a Long-Term Evolution (LTE), a New Wireless (New Radio, NR) access technology, a Wireless Local Area Network (WLAN), a bluetooth technology, a Wireless peer-to-peer (peer-to-peer) Network technology, and so on.

The plurality of electronic devices may be any suitable devices. In an exemplary embodiment, one of the first electronic device 110 and the second electronic device 160 is an interface node (interface node) in a telecommunication service provider, and the other is a terminal device (terminal device). For example, the first electronic device 110 is an interface node, and the second electronic device 160 is a terminal device. Alternatively, the first electronic device 110 is a terminal device and the second electronic device 160 is an interface node. In another example, the first electronic device 110 and the second electronic device 160 are both terminal devices.

In an embodiment, the first electronic device 110 is an interface Node in a telecommunication service provider, such as a base transceiver station, a Node B, an evolved Node B (eNB), and the like. The first electronic device 110 includes hardware components and software components to enable wireless communication between the first electronic device 110 and a terminal device having a subscription service at a telecommunication service provider, such as the second electronic device 160, etc. The first electronic device 110 is suitably coupled to other suitable nodes, such as a core node in a backbone network (backbone) of a telecommunication service provider, other interface nodes of the telecommunication service provider, and the like.

In addition, in the present embodiment, the second electronic device 160 is a terminal device. In an exemplary embodiment, the second electronic device 160 is a UE for mobile communication of an end user, such as a mobile phone, a smart phone, a tablet computer, a notebook computer, a wearable device, and the like. In another example, the second electronic device 160 is a stationary device (e.g., a desktop device). In another example, the second electronic device 160 is a machine type communication device, such as a wireless sensor, an Internet of Things (IoT) device, and the like.

According to an aspect of the invention, an electronic device, such as the first electronic device 110, is configured to generate a reference signal based on one or more LDPB sequences for synchronization and/or identification. In one embodiment, the LDPB sequence may be derived from a binary sequence (binary sequence) having a 0-valued position and a non-0-valued position. In an example, the LDPB sequence has at least one 0-valued location and at least two non-0-valued locations. The non-0 value positions are selected to achieve a desired autocorrelation (autocorrelation) characteristic. For example, the non-0 value positions are selected to minimize number overlap (e.g., the number of overlaps is less than a threshold) of non-0 value positions between the root (root) LDPB sequence and the shifted copy (copy) of the root LDPB sequence (e.g., cyclically shifted or non-cyclically shifted). In general, the density of non-0 value positions in the LDPB sequence is less than a threshold, such as below 1/2. While the LDPB sequence is boosted (e.g., increased by a value other than 0) to match the total power to the correlation sequence (for example only). In an example, the correlation sequence has the same length (e.g., total number of positions) as the LDPB sequence, and all positions are non-0 values.

In one example, the non-0 position may be selected to achieve a desired cyclic autocorrelation characteristic. In an exemplary case of ideal cyclic autocorrelation characteristics, any two cyclically shifted sequences originating from the same root LDPB sequence have at most one overlapping non-0 value position when their cyclic shifts are different.

In one embodiment, the LDPB sequence is constructed based on a Circular Golomb Rule (CGR) sequence. Among them, the CGR sequence has ideal circular autocorrelation characteristics.

In an example, a binary sequence having a length L (e.g., the total number of positions of the binary sequence) can be represented by equation 1:

in the binary sequence, when a location has a binary 0, the location may be referred to as a 0-value location. When a location has a binary 1, the location may be referred to as a non-0 value location. Binary sequence

The number of non-0 value positions in (a) is denoted by P.

Can be shifted by a cyclic shift of τ positions (τ being an integer)

And (4) showing. In one example, when the binary sequence is a binary sequence

When equation 2 is satisfied:

then binary sequence

Has ideal circular autocorrelation property and is binary sequence

Referred to as CGR with P non-0 positions. Wherein,<·>an inner product (inner product) between two vectors is represented. The CGR sequence can be used for constructing the LDPB sequence with ideal circular autocorrelation characteristics.

Furthermore, in one embodiment, to construct a CGR having P non-0 positions, the shortest sequence length L_minSatisfies equation 3

L_minP × (P-1) +1 equation 3

Further, theoretically, when (P-1) is prime power (prime power) which can be expressed by equation 4:

P-1＝R^Nequation 4

Having the shortest sequence length L_minOne or more CGR sequences of (a). Wherein R is prime number (such as 2,3,5,7,11,13,17 …), and N is positive integer (such as 1,2,3, …).

CGR sequences can be constructed by a variety of methods. In one embodiment, the CGR sequence may be generated using an exhaustive search (exhaustive search). In one example, an exhaustive search is performed by the electronic device to find CGR sequences corresponding to a different number of non-0 positions. The electronic device may be the first electronic device 110, the second electronic device 160, a processor (not shown) at a core node of a telecommunication service provider, or any other device. The results of the exhaustive search (e.g., CGR sequences corresponding to a non-0 number of locations) are stored in a memory in an electronic device (e.g., first electronic device 110, second electronic device 160, a core node of a telecommunication service provider, etc.). The stored CGR sequences may be used for synchronization and device identification by an electronic device, such as first electronic device 110. Appendix a shows an example of an exhaustive search result for 12 non-0-valued positions (P ═ 12), finding 36 LDPB root sequences for the shortest sequence length of 133.

In another embodiment, the CGR sequence may be constructed in an online session operation. In one example, the CGR sequence is constructed based on a construction algorithm, such as the algorithm disclosed in "A Theoren Fine project Geometry and Some Applications to Number Theory" of SINGER in American physical Society (1938, 377-385).

In general, the density of non-0 positions in a CGR sequence is relatively low (e.g., about 1/(P-1)), particularly when the number P of non-0 positions is large. For example, according to equation 3, when the number of non-0-valued positions P is 3, the shortest sequence length L of the CGR sequence_minIs 7 and the density of the non-0 position is below 1/2. According to equation 3, the shortest sequence length L of a CGR sequence when the number P of non-0-valued positions is 4_minIs 13 and the density of the non-0 position is below 1/3. According to equation 3, the shortest sequence length L of a CGR sequence when the number P of non-0-valued positions is 5_minIs 21 and the density of the non-0 position is below 1/4. According to equation 3, the shortest sequence length L of a CGR sequence when the number P of non-0-valued positions is 10_minAt 91, the density of the non-0 position was less than 1/9.

Further, according to an aspect of the present invention, the power at positions other than 0 value in the CGR sequence may be appropriately boosted to construct the LDPB sequence such that the total power of the signal transmitted according to the LDPB sequence is approximately equivalent to the total power of the signal transmitted according to the relevant sequence (e.g., it has the same length as the LDPB sequence, and has other than 0 value at all positions).

According to another aspect of the present invention, the LDPB sequence can be constructed based on a non-cyclic binary sequence, such as a Golomb Ruler (GR) sequence, in which the distance between any two pairs of non-0-valued positions is different. In the GR sequence example, the number of non-0 value positions is the order of the GR sequence, and the length of the GR sequence corresponds to the last non-0 value position. For example, a length 73 11-step GR sequence has a non-0 value at positions 0,1,4,13,28,33,47,54,64,70, 72.

In accordance with an aspect of the present invention, communication system 100 is configured to perform synchronization and device identification using a set of sequences generated from the same root LDPB sequence. In an example, the set of sequences includes a root LDPB sequence, cyclic and/or non-cyclic shifted copies of the root LDPB sequence. In one example, the set of sequences may be assigned to different devices for device identification. In another example, two or more sequences in the set of sequences may be assigned to a device, such as the electronic device 110, so that the first electronic device 110 may signal different information using the two or more sequences, respectively.

In one embodiment, communication system 100 may utilize a set of sequences generated by a plurality of root LDPB sequences for synchronization and device identification. In an example, multiple root LDPB sequences may be selected to have a lower number of cross-repeats (cross-repeats). In an example, a first CGR sequence of length 133 and a second CGR sequence of length 133 are selected. The first CGR sequence includes positions other than 0 at 0,1,3,12,20,34,38,81,88,94,104 and 109, and the second CGR sequence includes positions other than 0 at 0,1,25,30,40,46,53,96,100,114,122 and 131. In an exemplary embodiment, the maximum cross-correlation (e.g., cross-repetition) of the first CGR sequence and the second CGR sequence is 2. In this example, the set of sequences may include a first CGR sequence, cyclically and/or non-cyclically shifted copies of the first CGR sequence, a second CGR sequence, and cyclically and/or non-cyclically shifted copies of the second CGR sequence.

In particular, in the example shown in fig. 1, the first electronic device 110 includes a first transceiver 113, a first baseband processing circuit 120, and an LDPB sequence providing circuit 140 coupled together. In an embodiment, the first baseband processing circuit 120 includes a transmit processing circuit 130 configured to encode reference signals, such as PSS, SSS, and identification signals, based on the LDPB sequence. The first electronic device 110 may include other suitable components (not shown), such as a processor, a memory, and the like.

The second electronic device 160 includes a second transceiver 163 and a second baseband processing circuit 170 coupled together. The second baseband processing circuit 170 includes a receive processing circuit 180 for detecting the reference signal. Wherein the reference signal is encoded based on the LDPB sequence. The second electronic device 160 may include other suitable components (not shown), such as a processor, memory, etc.

It is noted that the communication system 100 may include other devices configured similarly to the first electronic device 110 or the second electronic device 160.

It is noted that the first baseband processing circuit 120 may include other suitable components, such as a receiving processing circuit (not shown). Similarly, the second baseband processing circuit 170 may include other suitable components, such as transmit processing circuitry (not shown), and so forth.

The first transceiver 113 is used to receive and transmit wireless signals. In an example, the first transceiver 113 includes a receive circuit RX 116 and a transmit circuit TX 115. The receive circuit RX 116 is operative to generate electrical signals in response to the electromagnetic waves captured by the antenna 114 and process the electrical signals to extract digital samples therefrom. For example, receive circuit RX 116 may filter, amplify, downconvert, and digitize an electrical signal to generate digital samples. The receive circuitry RX 116 may provide the digital samples to the first baseband processing circuitry 120 for further processing.

In an exemplary embodiment, the transmit circuit TX 115 is configured to receive a digital stream (e.g., output samples) from the first baseband processing circuit 120, process the digital stream to generate a Radio Frequency (RF) signal, and cause the antenna 114 to transmit electromagnetic waves into the air to carry the digital stream. In an example, the transmit circuit TX 115 may convert a digital stream into an analog signal and amplify, filter, and upconvert the analog signal to generate an RF signal.

In the example shown in fig. 1, LDPB sequence providing circuit 140 is configured to provide one or more LDPB sequences to transmit processing circuit 130. In an exemplary embodiment, the LDPB sequence providing circuit 140 is implemented as a memory circuit that stores LDPB sequences. The LDPB sequence is predetermined by an exhaustive search or theoretical construction. In an example, the LDPB sequence is allocated to the first electronic device 110. The LDPB sequence may be stored in any suitable form. In an example, the LDPB sequence is stored in the form of a plurality of non-0 value positions.

In one embodiment, the LDPB sequence is stored with the phase modulation configuration. In an example, the LDPB sequence is used to encode the reference signal in the frequency domain. The phase modulation configuration is predetermined to minimize a Peak to Average Power Ratio (PAPR) in the time domain, such as to optimize the performance of a Power amplifier (not shown) in the first transceiver 113. In one example, Binary Phase Shift Keying (BPSK) is used for Phase modulation. Each non-0 value position may then select one phase from the two phases for phase modulation. In one example, selected phase combinations for the LDPB sequence are tested to determine the phase modulation configuration with the lowest PAPR.

It is noted that the LDPB sequence providing circuit 140 can be implemented using other suitable circuits. In another example, LDPB sequence provision circuit 140 may be implemented as a processor that executes software instructions to generate one or more LDPB sequences over the air. In another example, LDPB sequence provision circuit 140 is implemented with logic circuitry (e.g., a sequence generator circuit) configured to generate one or more LDPB sequences over the air. In another example, the LDPB sequence providing circuit 140 is implemented with a communication interface circuit configured to receive one or more LDPB sequences from an external source (external source) located outside the first electronic device 110. Wherein the external source is, for example, a core node of a telecommunication service provider.

In accordance with an aspect of the invention, the transmit processing circuit 130 is configured to receive one or more LDPB sequences and encode one or more reference signals based on the one or more LDPB sequences. Where reference signals are used for synchronization and/or device identification, such as PSS, SSS, etc. In addition, in one embodiment, transmit processing circuitry 130 may appropriately encode other information (e.g., data and control information) and generate a digital stream (e.g., output samples) in response to the encoded reference signal, data, and control information.

It is noted that one or more LDPB sequences can be mapped and used in various domains, such as time domain, frequency domain, two-dimensional time-frequency domain, etc. In an embodiment, the transmit processing circuit 130 may encode the reference signal in the time domain based on one or more LDPB sequences. In an exemplary embodiment, the non-0 value is placed on a different time stamp (time mark) corresponding to the position of the non-0 value in the LDPB sequence.

In another embodiment, the transmit processing circuitry 130 may encode the reference signal in the frequency domain based on one or more LDPB sequences. In an example, a non-0 value is placed on a particular subcarrier corresponding to a position of the non-0 value in the LDPB sequence.

In another embodiment, the transmission processing circuit 130 may encode the reference signal in the two-dimensional video domain based on one or more LDPB sequences. For example, in an Orthogonal Frequency Division Multiplexing (OFDM) system, a set of resource elements is employed to carry a reference signal, each resource element corresponding to a particular subcarrier in the Frequency domain and a particular symbol in the time domain. In this example, the sending processing circuit 130 may map the LDPB sequence onto the set of resource elements. For example, the sending processing circuitry 130 may place a non-0 value on a resource element that maps to a non-0 value position in the LDPB sequence. In one embodiment, the non-0 value is a complex value (complex value) for phase modulation and power boost, and the waveform is modulated according to the complex value and the position of the resource element. In various embodiments, the non-0 value is constant, phase modulated, or amplitude modulated.

It is noted that, in an exemplary embodiment, the set of resource elements can be any set of resource elements.

In accordance with an aspect of the present invention, the transmit processing circuit 130 may also process other information, such as control information, data, and the like. For example, the transmit processing circuit 130 may process the data according to a suitable channel coding technique, wherein the channel coding technique may be an error detection coding technique, a rate matching coding technique, a Low Density Parity Check (LDPC) coding technique, a polar coding technique (polar coding), and the like. In one example, data may be appropriately modulated and multiplexed to generate OFDM symbols. The OFDM symbols are then interleaved (interleaved) and mapped onto the resource elements allocated for data transmission.

The transmission processing circuit 130 then generates a digital stream based on the resource element mapping results of various information processes such as reference signal processing, data processing, downlink control information processing, and the like.

It is noted that the transmit processing circuit 130 may perform other suitable functions, such as scrambling (scrambling), etc. Note that the transmission processing circuit 130 may be implemented using various techniques. In an example, the transmit processing circuit 130 is implemented as an integrated circuit. In another example, the transmit processing circuit 130 may be implemented as one or more processors executing software instructions.

According to an aspect of the present invention, the reference signal may be detected by the second electronic device 160 to provide time synchronization information, frequency synchronization information, device identification, subcarrier spacing of data channels, location of carrier center frequency, etc. to the second electronic device 160.

In the second electronic device 160, the second transceiver 163 is used to receive and transmit wireless signals. In an example, the second transceiver 163 includes a receive circuit RX 166 and a transmit circuit TX 165. The receive circuit RX 166 is operative to generate electrical signals in response to the electromagnetic waves captured by the antenna 164 and process the electrical signals to extract digital samples therefrom. For example, the receive circuit RX 166 may filter, amplify, downconvert, and digitize an electrical signal to generate digital samples. The receive circuitry RX 166 may provide the digital samples to the second baseband processing circuitry 170 for further processing.

In an exemplary embodiment, the transmit circuit TX 165 is configured to receive digital streams (e.g., output samples) from the second baseband processing circuit 170, process the digital streams to generate RF signals, and cause the antenna 164 to transmit electromagnetic waves into the air to carry the digital streams. In an example, the transmit circuit TX 165 may convert the digital stream into an analog signal and amplify, filter, and upconvert the analog signal to generate an RF signal.

In accordance with an aspect of the present invention, receive processing circuitry 180 is operative to receive digital samples from receive circuitry RX 166. Based on the digital samples, the receive processing circuit 180 detects one or more reference signals encoded based on the LDPB sequence and establishes time and/or frequency synchronization with the first electronic device 110 based on the LDPB sequence.

It is noted that although the example shown in fig. 1 employs one antenna per device, communication system 100 may be adapted to employ Multiple-Input Multiple-Output (MIMO) antenna techniques.

Fig. 2 is a flow diagram of a process 200 according to an embodiment of the invention. In an example, the process 200 is executed by the first electronic device 110 to transmit a wireless signal including one or more reference signals. Wherein the reference signal is encoded based on an LDPB sequence. The process starts at S201 and proceeds to S210.

In S210, one or more LDPB sequences are received. In the example shown in fig. 1, the first baseband processing circuit 120 receives one or more LDPB sequences from the sequence providing circuit 140.

In S220, the reference signal is encoded based on the LDPB sequence. In the example shown in fig. 1, the transmit processing circuit 130 may encode the reference signal in two-dimensional time-frequency domain based on one or more LDPB sequences. In an exemplary example of an OFDM system, a set of resource elements is used to carry reference signals, and each resource element corresponds to a particular subcarrier in the frequency domain and a particular symbol in the time domain. In this example, the sending processing circuit 130 may map the LDPB sequence onto the set of resource elements. For example, the sending processing circuitry 130 may place a non-0 value on a resource element that maps to a non-0 value position in the LDPB sequence. In one embodiment, the non-0 value is a complex value for phase modulation and power boost. Further, the waveform is modulated according to the complex value and the position of the resource element.

In S230, a digital stream is generated based on various information processes. In the example shown in fig. 1, the transmit processing circuit 130 generates a digital stream based on resource element mapping results of various information processes (e.g., reference signal processing, data processing, downlink control information processing).

In S240, a wireless signal is transmitted in response to the digital stream. In the example shown in fig. 1, the transmit circuit TX 115 receives a digital stream from the first baseband processing circuit 120, processes the digital stream to generate an RF signal, and causes the antenna 114 to transmit electromagnetic waves into the air to carry the digital stream. The process then proceeds to S299 and ends.

Fig. 3 is a diagram 300 illustrating an exemplary LDPB sequence according to an embodiment of the invention. Graph 300 represents non-0 value locations with solid rectangles and 0 value locations with empty rectangles. The LDPB sequence is a CGR with 4 positions of non-0 values, the length of the LDPB sequence is 13, and the density of non-0 values is below 1/3.

Graph 300 includes a root sequence 310 and a plurality of circularly shifted copies 321-332. The LDPB sequence in the example shown in fig. 3 has ideal cyclic autocorrelation properties. For example, any two of 310 and 321-332 have at most one non-0 value position that overlaps.

Fig. 4 is a diagram of a graph 400 employing LDPB sequences in different domains, according to an embodiment of the invention. Graph 400 represents non-0 value locations with solid rectangles and 0 value locations with empty rectangles. The LDPB sequence is a CGR with 5 positions of non-0 values, the length of the LDPB sequence is 21, and the density of non-0 values is below 1/4.

Graph 400 includes a first mapping 410 of LDPB in the time domain. Each position in the LDPB sequence can be mapped to a time scale in the time scale according to the first mapping 410.

Graph 400 includes a second mapping 420 of LDPB in the frequency domain. Each position in the LDPB sequence can be mapped onto a subcarrier in the frequency domain according to a second mapping 420.

Graph 400 includes a third mapping 430 of LDPB in the two-dimensional time-frequency domain. Each position in the LDPB sequence can be mapped onto a resource element in the two-dimensional time domain according to a third mapping 430.

Appendix A: p is 12, L_min133 th exhaustive search result

When implemented in hardware, the hardware may include one or more of discrete components, Integrated circuits, Application Specific Integrated Circuits (ASICs), and the like.

While the present invention has been described above with reference to specific embodiments for illustrative purposes, the present invention is capable of modification, decoration and variation. Accordingly, the above embodiments are for illustrative purposes only and are not intended to limit the present invention. Modifications may be made without departing from the scope of the claims of the present invention.

Claims

1. An apparatus for communication, the apparatus comprising:

baseband processing circuitry to encode a reference signal based on a particular sequence to generate a digital stream, wherein the particular sequence has a non-0 value at P selected positions and a number of non-0 value position overlaps between the particular sequence and a shifted copy of the particular sequence is less than a threshold, the length of the particular sequence is equal to or greater than Px (P-1) +1, P being a positive integer greater than 2; and

a transmit circuit to transmit a wireless signal in response to the digital stream.

2. The apparatus of claim 1, wherein the baseband processing circuitry is to encode one or more reference signals based on the particular sequence for synchronization and/or apparatus identification.

3. The apparatus of claim 1, wherein the baseband processing circuitry is to encode the reference signal in at least one of a time domain, a frequency domain, or a time-frequency domain based on the particular sequence.

4. The apparatus of claim 1, wherein the baseband processing circuit is to encode the reference signal based on the particular sequence, wherein the non-0 value is constant, phase modulated, or amplitude modulated.

5. The apparatus of claim 1, wherein the baseband processing circuitry is to encode the reference signal in a frequency domain based on the particular sequence, wherein the non-0 value is phase modulated to minimize a peak-to-average power ratio in a time domain.

6. The apparatus of claim 1, further comprising:

a sequence providing circuit for providing the specific sequence to the baseband processing circuit.

7. The apparatus of claim 6, wherein the sequence providing circuit includes a memory to store the particular sequence.

8. The apparatus of claim 6, wherein the sequence providing circuit comprises a sequence generator circuit to generate the particular sequence.

9. The apparatus of claim 6, wherein the sequence providing circuit comprises an interface circuit to receive the particular sequence from an external source external to the apparatus.

10. A method for communication, comprising:

receiving a particular sequence having a non-0 value at P selected positions, wherein a number of non-0 value position overlaps between the particular sequence and a shifted copy of the particular sequence is less than a threshold, the particular sequence has a length equal to or greater than Px (P-1) +1, P being a positive integer greater than 2;

encoding a reference signal based on the particular sequence to generate a digital stream; and

a wireless signal is transmitted in response to the digital stream.

11. The method for communicating of claim 10, wherein encoding the reference signal based on the particular sequence to generate the digital stream further comprises:

one or more reference signals are encoded based on the particular sequence for synchronization and/or device identification.

12. The method for communicating of claim 10, wherein encoding the reference signal based on the particular sequence to generate the digital stream further comprises:

encoding the reference signal in at least one of a time domain, a frequency domain, or a time-frequency domain based on the particular sequence.

13. The method for communicating of claim 10, wherein encoding the reference signal based on the particular sequence to generate the digital stream further comprises:

encoding the reference signal based on the particular sequence, wherein the non-0 value is constant, phase modulated, or amplitude modulated.

14. The method for communicating of claim 10, wherein encoding the reference signal based on the particular sequence to generate the digital stream further comprises:

encoding the reference signal in a frequency domain based on the specific sequence, wherein the non-0 value is phase-modulated to minimize a peak-to-average power ratio in the time domain.

15. The method for communicating of claim 10, wherein receiving the particular sequence having a value other than 0 at the selected location comprises:

storing the particular sequence in a memory; and

the memory is accessed to receive the particular sequence.

16. The method for communicating of claim 10, wherein receiving the particular sequence having a value other than 0 at the selected location comprises:

generating, by a sequence generator circuit, the particular sequence; and

receiving the particular sequence from the sequence generator circuit.

17. The method for communicating of claim 10, wherein receiving the particular sequence having a value other than 0 at the selected location comprises:

the specific sequence is received from an external source.

18. The method for communicating of claim 16, wherein generating the particular sequence by the sequence generator circuit comprises at least one of: searching the specific sequence and theoretically constructing the specific sequence.