CN111385006A - mmWave channel estimation method - Google Patents

Abstract

A millimeter wave channel estimation method includes performing channel measurement on a millimeter wave channel to generate a first measurement matrix according to a first beamforming matrix, and estimating at least one angle of transmission (AOD) of the millimeter wave channel according to the first measurement matrix and an angle compressed sensing matrix. The first beamforming matrix comprises a plurality of first beamforming vectors, the plurality of first beamforming vectors respectively correspond to a plurality of first beamforming modes, and the first measurement matrix comprises a plurality of first measurement parameters respectively corresponding to the plurality of first beamforming vectors.

Description

mmWave channel estimation method

technical field

The present invention relates to a channel estimation method, in particular to a millimeter wave channel estimation method.

Background technique

With the development of wireless communication technology, in order to meet the demands of higher speed and larger bandwidth, the fifth generation mobile communication standard has been established. However, the middle and low frequency bands in today's spectrum are mostly used by other wireless communication technologies, so the application of millimeter waves in the high frequency band becomes the focus of future wireless communication technologies.

Currently, millimeter wave channel estimation is performed using an exhaustive search method. The implementation of the exhaustive search method is to transmit a beam for each analysis angle and receive the beam at the receiving end to generate measurement data and perform operations to estimate the channel. However, as the requirements for resolution continue to increase, the number of measurements and the amount of computation of this method also increase significantly, resulting in a large consumption of time resources.

SUMMARY OF THE INVENTION

In view of the above, the present invention provides a millimeter wave channel estimation method.

A millimeter-wave channel estimation method according to an embodiment of the present invention includes sending a signal through a millimeter-wave channel according to a first beamforming matrix, performing channel measurement on the millimeter-wave channel to generate a first measurement matrix, and compressing an angle according to the first measurement matrix The sensing matrix is estimated to obtain at least one angle of departure (AOD) of the millimeter wave channel. Wherein, the first beamforming matrix includes a plurality of first beamforming vectors, the plurality of first beamforming vectors respectively correspond to a plurality of first beamforming modes, and the first measurement matrix includes a plurality of first beamforming vectors respectively corresponding to the plurality of A plurality of first measurement parameters for a beamforming vector.

A method for estimating a millimeter wave channel according to another embodiment of the present invention includes, according to a first beamforming matrix, receiving signals through a millimeter wave channel to generate a first measurement matrix, and estimating according to the first measurement matrix and the angular compressed sensing matrix to obtain at least one angle of arrival (AOA) of the millimeter wave channel. Wherein, the first beamforming matrix includes a plurality of first beamforming vectors, the plurality of first beamforming vectors respectively correspond to a plurality of first beamforming modes, and the first measurement matrix includes a plurality of first beamforming vectors respectively corresponding to the plurality of A plurality of first measurement parameters for a beamforming vector.

Through the above structure, the millimeter-wave channel estimation method disclosed in this case forms multiple beamforming vectors based on the compressed sensing theory, thereby generating multiple measurement parameters related to the millimeter-wave channel, and then utilizes the compressed sensing restoration technology from the multiple beamforming vectors. The measurement parameters, the beamforming vectors, and the angle parameters obtain the angle characteristic estimation result of the millimeter-wave channel. The millimeter-wave channel estimation method disclosed in this case does not need to perform the step of feeding back measurement information, and can estimate the characteristic parameters of the channel through a small number of measurements, so as to achieve fast millimeter-wave channel estimation, thereby improving subsequent signals/data quality of delivery.

The foregoing description of the present disclosure and the following description of the embodiments serve to demonstrate and explain the spirit and principles of the present invention, and provide further explanation for the claims of the present invention.

Description of drawings

FIG. 1 is a flowchart of a millimeter wave channel estimation method according to an embodiment of the present invention.

FIG. 2 is a flow chart of steps of forming a first beamforming matrix in a method for millimeter wave channel estimation according to an embodiment of the present invention.

FIG. 3 is a functional block diagram of a communication system according to an embodiment of the present invention.

FIG. 4 is a flow chart showing the steps of generating a measurement matrix in a millimeter-wave channel estimation method according to an embodiment.

FIG. 5 is a flowchart of a millimeter wave channel estimation method according to another embodiment of the present invention.

FIG. 6 is a flow chart of steps of forming a second beamforming matrix in a millimeter-wave channel estimation method according to another embodiment of the present invention.

Symbol Description

1 Communication system

10 base stations

101 Baseband circuit

103 RF Link

105 Signal Transceivers

1051 Phase Modulation Circuit

1053 Impedance Modulation Circuit

1055 Antenna

20 Clients

30 mmWave channel

S11～S13, S111～S119, S121～S129 Steps

S21～S26, S241～S245 Steps

Detailed ways

The detailed features and advantages of the present invention are described in detail below in the embodiments, and the contents are sufficient to enable any person skilled in the art to understand the technical content of the present invention and implement accordingly, and according to the contents disclosed in this specification, claims and drawings, Objects and advantages associated with the present invention can be readily understood by any person skilled in the art. The following examples further illustrate the concepts of the invention in further detail, but are not intended to limit the scope of the invention in any way.

The millimeter-wave channel estimation method provided by the present invention is suitable for a communication system that transmits wireless signals through a millimeter-wave channel. Please refer to FIG. 1 . FIG. 1 is a flowchart of a method for estimating a millimeter wave channel according to an embodiment of the present invention. In step S11, the above-mentioned communication system for transmitting wireless signals through a millimeter wave channel forms a first beamforming matrix, and the first beamforming matrix includes a plurality of first beamforming vectors corresponding to the plurality of first beamforming vectors respectively. model. It should be noted here that the above-mentioned step S11 of forming the first beamforming matrix is an optional step, that is, in other embodiments, the first beamforming matrix may be pre-stored in the communication system, so when the millimeter wave is executed In the channel estimation method, only the following steps S12 and S13 may be performed.

In step S12, the communication system generates a first measurement matrix associated with the millimeter-wave channel according to the first beamforming matrix formed in step S11, wherein the first measurement matrix includes a plurality of first measurement parameters corresponding to the first beamforming respectively. a plurality of first beamforming vectors in the matrix. Further, the plurality of first measurement parameters in the first measurement matrix may have a one-to-one relationship with the plurality of first beamforming vectors in the first beamforming matrix. In an embodiment, the method for the communication system to generate the first measurement matrix associated with the millimeter-wave channel according to the first beamforming matrix may be to transmit a signal via the millimeter-wave channel according to the first beamforming matrix and perform channel measurement on the millimeter-wave channel; In another embodiment, the first measurement matrix may be generated by receiving signals through a millimeter-wave channel according to the first beamforming matrix. The architecture for operating the two embodiments will be described in detail later.

In step S13, the communication system performs estimation according to the first measurement matrix and the angular compressed sensing matrix to obtain the angular characteristic estimation result of the mmWave channel. The angle compressive sensing matrix includes the aforementioned first beamforming matrix and an angle matrix, wherein the angle matrix includes a plurality of angle parameters, each angle parameter has a base and an exponent, and the base is, for example, a mathematical constant (e), and the exponent is. then contain different angle values respectively. For example, the angle parameter may be e ^jkdsinθi .

Please refer to FIG. 2 to further describe the steps of forming the first beamforming matrix in step S11 of FIG. 1 . FIG. 2 is a flow chart of steps of forming a first beamforming matrix in a method for millimeter wave channel estimation according to an embodiment of the present invention. In step S111, the communication system establishes a basic compressed sensing matrix. The basic compressed sensing matrix is, for example, a Gabor Frame, which is a matrix of one dimension m*m ² . In particular, m can be a prime number above 5, which means that the dimension of the Gabor frame can be greater than 5*25. In an embodiment, the Gabor framework may be formed by an exponential function, wherein the base of the exponential function is a mathematical constant (e), and its exponent includes a constant m, which is associated with the number of measurements performed in the subsequent estimation step. For example, the basic compressed sensing matrix _AG can be represented by the following mathematical formula:

其中，i₁,i₂,i₃＝0,1,…,m-1，亦即，i₁可以为0、1、……、m-2或m-1；i₂可以为0、1、……、m-2或m-1；且i₃可以为0、1、……、m-2或m-1。

Wherein, i ₁ , i ₂ , i ₃ = 0, 1, ..., m-1, that is, i ₁ can be 0, 1, ..., m-2 or m-1; i ₂ can be 0, 1 , ..., m-2 or m-1; and i ₃ may be 0, 1, ..., m-2 or m-1.

Next, in step S113, the communication system performs a least squares operation on the basic compressed sensing matrix to obtain a first least squares matrix. In detail, the communication system will design the precoding matrix F, calculate the matrix product of the conjugate transpose matrix of the angle matrix A _θ and the precoding matrix F, and then obtain the transposed matrix and the matrix product of the basic compressed sensing matrix A _G. Differentiate the matrix solution F _opt of the precoding matrix with the least square sum, and use the matrix product of the transposed matrix of this matrix solution F _opt and the conjugate transposed matrix of the angle matrix A _θ as the first least square matrix A _LS . The calculation process of step S113 can be exemplarily presented by the following mathematical formula:

令

make

In step S115, the communication system performs a normalization operation on the first least square matrix obtained in step S113 to obtain a normalization matrix, wherein the detailed operation content of the normalization operation is understood by those skilled in the art to which the present invention belongs. , will not be repeated here. In step S117 , the communication system performs a least squares operation on the normalized matrix again to obtain a second least squares matrix, wherein the detailed operation content of the least squares operation is similar to the aforementioned step S113 , and details are not repeated here. In step S119, the communication system multiplies the second least square matrix by the inverse matrix of the angle matrix to obtain the first beamforming matrix.

As mentioned above, the millimeter-wave channel estimation method provided by the present invention is suitable for a communication system that transmits wireless signals through a millimeter-wave channel. Further, please refer to FIG. 1 , FIG. 3 and FIG. 4 to describe the embodiment of the communication system and the detailed mmWave channel estimation method. 3 is a functional block diagram of a communication system according to an embodiment of the present invention; and FIG. 4 is a flow chart of generating steps of a measurement matrix in a millimeter wave channel estimation method according to an embodiment.

As shown in FIG. 3 , the communication system 1 includes a base station 10 and a user terminal 20 , both of which transmit wireless signals through a millimeter wave channel 30 . The base station 10 includes a baseband circuit 101 , a radio frequency link 103 and a plurality of signal transceivers 105 , wherein each signal transceiver 105 includes a phase modulation circuit 1051 , an impedance modulation circuit 1053 and an antenna 1055 . The base station 10 may also include a signal generator and a precoder (eg, a computer), or be externally connected to the signal generator and precoder in the communication system 1 . The UE 20 can receive wireless signals from the base station 10 through the millimeter wave channel 30 to perform data downloading, and can also transmit wireless signals to the base station 10 through the millimeter wave channel 30 to perform data uploading. For example, the client 20 may be a mobile phone, a notebook computer or other user devices having a wireless signal transceiver, which is not limited in the present invention.

In the embodiment, the communication system 1 can perform the estimation of the millimeter wave channel 30 by transmitting the wireless signal from the base station 10 and receiving it by the user terminal 20 , including steps S12 and S13 in the aforementioned FIG. 1 , or steps S11˜ S13. In step S11, the communication system 1 may form a beamforming matrix including a plurality of first beamforming vectors through the precoder of the base station 10, and the detailed forming steps are as described in the previous embodiments, and are not repeated here.

In step S12, the communication system 1 generates a first measurement matrix according to the first beamforming matrix. Further, the communication system 1 generates and transmits a beam through the base station 10 according to one of the plurality of first beamforming vectors formed in step S11. For example, the base station 10 may generate a beam having a radiation field corresponding to a first beamforming pattern of the first beamforming vector according to the first beamforming vector. In detail, each first beamforming vector includes a phase modulation value and an impedance modulation value of each antenna 1055, and the base station 10 can control the phase modulation circuit 1051 and the impedance modulation circuit of each signal transceiver 105 according to the first beamforming vector 1053, thereby adjusting the phase and amplitude of the electromagnetic waves (wireless signals) emitted by the antennas 1055, and the electromagnetic waves emitted by the antennas 1055 together form a radiation pattern with the first beamforming pattern corresponding to the first beamforming vector. . Next, the communication system 1 receives the beam through the UE 20 and generates the first measurement parameter. This first measurement parameter corresponds to the above-mentioned first beamforming vector for generating the beam, and is one of the parameters in the first measurement matrix.

In this embodiment, the wireless signal transmitting end is the base station 10 and the wireless signal receiving end is the user end 20 , and step S12 in FIG. 1 may include steps S121 , S123 , S125 , S127 and S129 shown in FIG. 4 . In step S121, the base station 10 generates and transmits a beam according to a beamforming vector (eg, the first one) in the beamforming matrix (ie, the first beamforming matrix) formed in step S11. In step S123, the UE 20 receives the beam from the base station 10 and passes through the millimeter wave channel 30, and generates corresponding measurement parameters accordingly. In step S125, the base station 10 determines whether the previously used beamforming vector is the last one in the beamforming matrix. If the determination result is no, as shown in step S127, the base station 10 will generate and transmit a beam according to the next beamforming vector in the beamforming matrix, and then the user terminal 20 will perform step S123; if the determination result is yes, then As shown in step S129, the user terminal 20 integrates the generated measurement parameters into a measurement matrix. Therefore, for example, if the beamforming matrix has m beamforming vectors, after the above steps, the wireless signal receiving end can correspondingly generate m measurement parameters to form an m*1 measurement matrix (ie, the first measurement matrix).

In short, the communication system 1 can generate beams multiple times according to multiple beamforming vectors through the base station 10, and receive the beams multiple times by the UE 20 times to generate multiple measurement parameters respectively, and integrate these measurement parameters into Measurement matrix. The embodiment of FIG. 4 exemplarily describes that the base station 10 generates beams sequentially according to the beamforming vectors in the beamforming matrix. However, the present invention does not limit the order in which the base station uses the beamforming vectors to be equal to the arrangement order in the matrix.

In step S13 , the UE 20 performs estimation according to the first measurement matrix and the angular compressive sensing matrix to obtain the angular characteristic estimation result of the millimeter-wave channel 30 . In this embodiment, the angle characteristic estimation result includes at least one angle of departure (AOD). In detail, the client 20 has a compressed sensing restoration algorithm, which for example includes the following mathematical formula:

y=φα.

Among them, y is the measurement matrix; φ is the angle compressed sensing matrix; α is the desired angle characteristic estimation result. As described in step S119 of forming the first beamforming matrix in the preceding column of FIG. 2 , the first beamforming matrix is obtained by multiplying the angle compressive sensing matrix (the second least squares matrix) by the inverse of the angle matrix. In other words, the millimeter wave channel estimation method proposed in this case will decompose the angle compressed sensing matrix into the first beamforming matrix and the angle matrix, as shown in the following mathematical formula:

Through the above restoration algorithm, the angle characteristic estimation result can be calculated by the first beamforming matrix generated in step S11 , the first measurement matrix measured in step S12 , and the known angle matrix. The angle characteristic estimation result includes a plurality of angle estimation parameters, these angle estimation parameters have a one-to-one relationship with the angle parameters in the angle matrix, and the angle estimation parameters can indicate whether there is any angle at the angle represented by the corresponding angle parameter. Whether a wireless signal (beam) is received or the strength of the received wireless signal is greater than a threshold. For example, when the signal receiving end receives a wireless signal strength through the millimeter wave channel at a specific angle that is not greater than the threshold, the angle estimation parameter corresponding to the specific angle is zero; and when the signal receiving end is at a specific angle When the received wireless signal strength through the millimeter wave channel is greater than the threshold, the angle estimation parameter corresponding to the specific angle is not zero.

Compared with the existing exhaustive search method, the measurement times of the millimeter-wave channel estimation method proposed in this case is determined by the parameter design of the beamforming matrix, so it will not increase with the improvement of the resolution, which can avoid high Due to the requirement of resolution, a large amount of measurement data and computing time are generated, so as to quickly complete the estimation of the millimeter-wave channel.

In another embodiment, the communication system 1 may perform the estimation of the millimeter wave channel 30 by transmitting the wireless signal from the UE 20 and receiving it by the base station 10 , including steps S12 and S13 or step S11 in the aforementioned FIG. 1 . ~S13. In step S11, the communication system 1 forms a first beamforming matrix including a plurality of first beamforming vectors through the base station 10, and the detailed forming steps are as described in the previous embodiments, and are not repeated here.

In step S12, the communication system 1 generates a first measurement matrix according to the first beamforming matrix. Further, the communication system 1 sends a signal through the user terminal 20, and then the base station 10 receives the signal through one of the plurality of first beamforming vectors formed in step S11 to generate the corresponding first measurement parameter. The first measurement parameter is one of the parameters in the first measurement matrix. In this embodiment, the base station 10 may receive signals multiple times through a plurality of first beamforming vectors respectively, so as to generate a plurality of first measurement parameters corresponding to the first beamforming vectors respectively. For example, the base station 10 may sequentially receive signals according to the first beamforming vectors in the first beamforming matrix, which is similar to the process shown in FIG. 4 above, but not limited thereto. The base station 10 may integrate the generated first measurement parameters into a first measurement matrix.

In step S13, the base station 10 may obtain the angle characteristic estimation result of the millimeter wave channel 30 according to the first measurement matrix, the angular compressed sensing matrix, the first beamforming matrix and the angular matrix. The angle characteristic estimation result includes at least one angle of arrival (AOA) of the received signal, and the base station 10 has a compressed sensing restoration algorithm. The mathematical formula included in the algorithm and the detailed operation process are similar to those in the previous embodiment. description, and therefore will not be repeated here. In this embodiment, the base station 10 has the functions of forming a beamforming vector and calculating an angular characteristic at the same time.

In another embodiment, both the base station 10 and the UE 20 of the communication system 1 have a compressed sensing restoration algorithm. Through the millimeter-wave channel estimation methods similar to the above two embodiments, the communication system 1 can perform millimeter-wave channel estimation no matter when the user terminal 20 performs uploading or downloading.

Please refer to FIG. 3 , FIG. 5 and FIG. 6 together. FIG. 5 is a flowchart of a method for estimating a millimeter wave channel according to another embodiment of the present invention, and FIG. 6 is another embodiment of the present invention. The illustrated flowchart of the steps of forming the second beamforming matrix in the mmWave channel estimation method. The millimeter-wave channel estimation method shown in FIG. 5 is also applicable to the communication system 1 shown in FIG. 3 . Therefore, the following will exemplarily describe the implementation content of the communication system 1 executing the millimeter-wave channel estimation method of FIG. 5 . In steps S21-S23, the communication system 1 forms a first beamforming matrix through the base station 10, generates a first measurement matrix associated with the millimeter wave channel 30 according to the first beamforming matrix, and compresses the angle according to the first measurement matrix The above-mentioned steps are similar to steps S11 to S13 in the embodiment of FIG. 1 , and the detailed implementation of each step is as described in the previous embodiments, so It will not be repeated here.

In the embodiment shown in FIG. 5 , after obtaining the angular characteristic estimation result of the mmWave channel 30 , the communication system 1 further uses the second beamforming matrix to perform the estimation of the mmWave channel 30 . In step S24, the communication system 1 forms a second beamforming matrix through the base station 10, wherein the second beamforming matrix includes a plurality of second beamforming vectors. Further, FIG. 6 illustrates an embodiment of forming the second beamforming matrix. In step S241, the base station 10 establishes a basic compressed sensing matrix, such as a Gabor frame. In step S243, the base station 10 performs a least squares operation on the compressed sensing matrix to obtain a least squares matrix. The above steps S241 and S243 are the same as the steps S111 and S113 in the previous embodiment of FIG. 2 , and the detailed contents are not repeated here. Next, in step S245, the base station 10 multiplies the least square matrix by the inverse matrix of the angle matrix to obtain a second beamforming matrix.

It should be noted here that, FIG. 5 exemplarily shows the step S24 of forming the second beamforming matrix after the step S23 of obtaining the angle characteristic estimation result. However, in other embodiments, the step S24 can also be executed in Before or after any one of the preceding steps S21 to S23, the present invention is not limited. In addition, as mentioned above, the steps S241 and S243 of forming the second beamforming matrix are the same as the steps S111 and S113 of forming the first beamforming matrix. Therefore, in the embodiment, the base station 10 performs step S21 to form the first beamforming matrix. A second beamforming matrix may be formed together in the process of beamforming matrix. In addition, the aforementioned step S21 and step S24 are both optional steps. In other embodiments, the first and second beamforming matrices may be stored in the communication system 1 in advance. Therefore, when executing the millimeter wave channel estimation method, only The aforementioned steps S22 and S23 and the later-described steps S25 and S26 are executed.

After obtaining the second beamforming matrix, the communication system 1 can estimate other characteristic parameters of the millimeter wave channel 30 by using the beamforming matrix, as shown in steps S25 to S26 in FIG. 5 . In step S25, the communication system 1 generates a second measurement matrix associated with the millimeter-wave channel 30 according to the second beamforming matrix, wherein the second measurement matrix includes a plurality of second measurement parameters corresponding to the plurality of second beams respectively. Shape vector. Further, there may be a one-to-one relationship between the second measurement parameter in the second measurement matrix and the second beamforming vector in the second beamforming matrix. The detailed implementation of step S25 is similar to the foregoing implementation of generating the measurement matrix according to the first beamforming matrix, and details are not described herein again.

In step S26 , the communication system 1 obtains the gain characteristic estimation result of the mmWave channel 30 according to the second measurement matrix gain compressive sensing matrix and the angle characteristic estimation result obtained in step S23 . Wherein, the gain compressed sensing matrix includes a second beamforming matrix and an angle matrix. Further, the communication system 1 can obtain the gain characteristic estimation result through the compressed sensing restoration algorithm mentioned in the foregoing embodiment, that is, obtain the gain corresponding to the angle characteristic estimation result according to the angle characteristic estimation result.

In the embodiment in which the signal is transmitted according to the second beamforming matrix and the channel measurement is performed, the gain characteristic estimation result obtained by the communication system 1 includes at least one transmit signal gain, and the at least one transmit signal gain corresponds to the first-stage estimation ( at least one transmit signal angle obtained in steps S21-S23); and in the embodiment in which the signal is received and the channel measurement is performed according to the second beamforming matrix, the gain characteristic estimation result obtained by the communication system 1 includes at least one received signal Gain, the at least one received signal gain corresponds to the at least one received signal angle obtained by the first stage estimation. After the above steps S21 to S26 are executed, the communication system 1 can obtain the estimated value of the transmitted signal angle or the received signal angle of the millimeter-wave channel 30 and the estimated value of the gain corresponding to the angle respectively through a two-stage estimation method. , to achieve accurate millimeter-wave channel estimation.

Through the above structure, the millimeter-wave channel estimation method disclosed in this case forms multiple beamforming vectors based on the compressed sensing theory, thereby generating multiple measurement parameters related to the millimeter-wave channel, and then utilizes the compressed sensing restoration technology from the multiple beamforming vectors. The measurement parameters, the beamforming vectors, and the angle parameters obtain the angle characteristic estimation result of the millimeter-wave channel. The millimeter-wave channel estimation method disclosed in this case does not need to perform the step of feeding back measurement information, and can estimate the characteristic parameters of the channel through a small number of measurements, so as to achieve fast millimeter-wave channel estimation, thereby improving subsequent signals/data quality of delivery. Further, compared with the estimation method in which all parameters are obtained in a single stage, a more accurate estimation result can be obtained by obtaining the angle characteristic parameters and gain characteristic parameters of the millimeter-wave channel respectively through two-stage estimation.

Claims (10)

1. A millimeter wave channel estimation method includes:

transmitting signals through a millimeter wave channel according to a first beamforming matrix, wherein the first beamforming matrix comprises a plurality of first beamforming vectors, and the first beamforming vectors correspond to a plurality of first beamforming modes respectively;

performing channel measurement on the millimeter wave channel to generate a first measurement matrix, wherein the first measurement matrix comprises a plurality of first measurement parameters respectively corresponding to the first beamforming vectors; and

estimating to obtain at least one transmitted signal angle of the millimeter wave channel according to the first measurement matrix and the angle compressed sensing matrix.

2. The millimeter wave channel estimation method according to claim 1, further comprising:

transmitting signals through the millimeter wave channel according to a second beamforming matrix, the second beamforming matrix comprising a plurality of second beamforming vectors, the second beamforming vectors corresponding to a plurality of second beamforming modes, respectively;

performing channel measurement on the millimeter wave channel to generate a second measurement matrix, wherein the second measurement matrix comprises a plurality of second measurement parameters respectively corresponding to the second beamforming vectors; and

estimating to obtain at least one transmission signal gain respectively corresponding to the at least one transmission signal angle according to the second measurement matrix, the gain compressed sensing matrix and the at least one transmission signal angle.

3. The millimeter wave channel estimation method of claim 1, further comprising forming the first beamforming matrix, wherein the step of forming the first beamforming matrix comprises:

establishing a basic compressed sensing matrix;

performing a least squares operation on the basic compressed sensing matrix to obtain a first least squares matrix;

performing a normalization operation on the first least square matrix to obtain a normalized matrix;

performing the least squares operation on the normalized matrix to obtain a second least squares matrix; and

the second least squares matrix is multiplied by the inverse of the angle matrix to obtain the first beamforming matrix.

4. The millimeter wave channel estimation method of claim 2, further comprising forming the second beamforming matrix, wherein the step of forming the second beamforming matrix comprises:

establishing a basic compressed sensing matrix;

performing a least squares operation on the basic compressed sensing matrix to obtain a least squares matrix; and

the least squares matrix is multiplied by the inverse of the angle matrix to obtain the second beamforming matrix.

5. The millimeter wave channel estimation method according to claim 3 or 4, wherein the basic compressed sensing matrix is a Gabor framework.

6. A millimeter wave channel estimation method includes:

receiving signals through a millimeter wave channel according to the first beam forming matrix to generate a first measurement matrix; and

estimating to obtain at least one received signal angle of the millimeter wave channel according to the first measurement matrix and the angle compressed sensing matrix;

the first measurement matrix includes a plurality of first measurement parameters respectively corresponding to the first beamforming vectors.

7. The millimeter wave channel estimation method according to claim 6, further comprising:

receiving signals through the millimeter wave channel according to a second beamforming matrix to generate a second measurement matrix; and

estimating to obtain at least one received signal gain respectively corresponding to the at least one received signal angle according to the second measurement matrix, the gain compressed sensing matrix and the at least one received signal angle;

the second beamforming matrix comprises a plurality of second beamforming vectors, the second beamforming vectors correspond to a plurality of second beamforming modes respectively, and the second measurement matrix comprises a plurality of second measurement parameters corresponding to the second beamforming vectors respectively.

8. The millimeter wave channel estimation method of claim 6 further comprising forming the first beamforming matrix, wherein the step of forming the first beamforming matrix comprises:

establishing a basic compressed sensing matrix;

performing a least squares operation on the basic compressed sensing matrix to obtain a first least squares matrix;

performing a normalization operation on the first least square matrix to obtain a normalized matrix;

performing the least squares operation on the normalized matrix to obtain a second least squares matrix; and

the second least squares matrix is multiplied by the inverse of the angle matrix to obtain the first beamforming matrix.

9. The millimeter wave channel estimation method of claim 7 further comprising forming the second beamforming matrix, wherein the step of forming the second beamforming matrix comprises:

establishing a basic compressed sensing matrix;

performing a least squares operation on the basic compressed sensing matrix to obtain a least squares matrix; and

multiplying the least squares matrix by the inverse of the angle matrix to obtain the second beamforming matrix.

10. The millimeter wave channel estimation method according to claim 8 or 9, wherein the basic compressed sensing matrix is a Gabor frame.

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