CN110149285B - Method for reducing phase error in high-order modulation of low bit quantization - Google Patents

Method for reducing phase error in high-order modulation of low bit quantization Download PDF

Info

Publication number
CN110149285B
CN110149285B CN201910347473.1A CN201910347473A CN110149285B CN 110149285 B CN110149285 B CN 110149285B CN 201910347473 A CN201910347473 A CN 201910347473A CN 110149285 B CN110149285 B CN 110149285B
Authority
CN
China
Prior art keywords
pilot
result
amplitude
phase
order modulation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201910347473.1A
Other languages
Chinese (zh)
Other versions
CN110149285A (en
Inventor
孙布勒
周一青
刘玲
原进宏
石晶林
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Institute of Computing Technology of CAS
Original Assignee
Institute of Computing Technology of CAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Institute of Computing Technology of CAS filed Critical Institute of Computing Technology of CAS
Priority to CN201910347473.1A priority Critical patent/CN110149285B/en
Publication of CN110149285A publication Critical patent/CN110149285A/en
Application granted granted Critical
Publication of CN110149285B publication Critical patent/CN110149285B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/0224—Channel estimation using sounding signals
    • H04L25/0228—Channel estimation using sounding signals with direct estimation from sounding signals

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Radio Transmission System (AREA)

Abstract

The invention provides a method for reducing phase error in high-order modulation of low bit quantization, which is suitable for data transmission of an uplink channel between a terminal and a base station, and comprises the following steps: step 1, a terminal generates and sends a pilot frequency sequence to a base station, wherein the pilot frequency sequence is divided into two pilot frequency subsequences with equal length; step 2, the base station carries out channel estimation according to each received pilot frequency symbol, and generates a multi-antenna merging vector of a pilot frequency subsequence according to the result of each channel estimation; and 3, the base station respectively performs multi-antenna combination on the received high-order modulation signals according to each multi-antenna combination vector, and obtains the phase and amplitude of an intermediate result according to the result of all multi-antenna combination and a preset phase difference, so as to obtain the detection result of the high-order modulation signals. By the technical scheme of the invention, the phase error generated during the modulation of the high-order signal in the low-bit-quantization massive MIMO system is reduced, and the precision of the actual channel estimation is improved.

Description

Method for reducing phase error in high-order modulation of low bit quantization
Technical Field
The present invention relates to the field of communications technologies, and in particular, to a method for reducing a phase error in high-order modulation of low bit quantization.
Background
Massive multiple-input-multiple-output (massive mimo) systems have become a key technology required to improve the throughput of fifth generation cellular systems (5G). However, the potentially high power consumption of the massiveMIMO system, especially the power consumption of the radio frequency link, has become a bottleneck limiting its practical application.
In order to reduce the power consumption of the rf link of the Massive MIMO system, an Analog to Digital Converter (ADC) module with low bit quantization is used as a solution. However, low bit quantization causes loss of signal amplitude and phase information, and the difference between the quantized signal and the signal before quantization is very large, which finally causes serious degradation of signal demodulation performance. Particularly, in the actual channel estimation, the phase information may generate a significant deviation, which causes a serious loss to the demodulation performance of the higher-order phase modulation. Wherein, the accuracy of the actual channel estimation depends on the length of the pilot sequence (composed of a series of pilot symbols), and the error of the actual channel estimation can be cancelled when the length of the pilot sequence is long enough.
In the prior art, the influence of actual channel estimation errors on the detection of high-order modulation signals can be reduced by increasing the length of the pilot sequence used for actual channel estimation. However, since the time-frequency resources available in wireless communication are limited, increasing the length of the pilot sequence results in excessive pilot overhead, and the time-frequency resources used for transmitting practically useful data signals are reduced, resulting in a decrease in effective throughput.
Disclosure of Invention
It is an object of the present invention to overcome the above-mentioned drawbacks of the prior art and to provide a method for reducing phase errors in high order modulation with low bit quantization.
According to the technical scheme of the invention, a method for reducing phase errors in high-order modulation of low bit quantization is provided, the method is suitable for data transmission of an uplink channel between a terminal and a base station in a large-scale multiple-input multiple-output system, the base station is provided with a plurality of antennas, and the method comprises the following steps:
step 1, a terminal generates and sends a pilot frequency sequence to a base station, wherein the pilot frequency sequence is divided into two pilot frequency subsequences with equal length, a preset phase difference is formed between the two pilot frequency subsequences, and the pilot frequency subsequences at least comprise a pilot frequency symbol;
step 2, the base station carries out channel estimation according to each pilot frequency symbol in each received pilot frequency subsequence respectively, and generates a multi-antenna merging vector corresponding to each pilot frequency symbol in each pilot frequency subsequence according to the result of each channel estimation;
and 3, the base station respectively performs multi-antenna combination on the received high-order modulation signals according to each multi-antenna combination vector, calculates an intermediate result according to the result of all multi-antenna combination and a preset phase difference, acquires the phase and amplitude of the intermediate result, and calculates the detection result of the high-order modulation signals according to the phase and amplitude of the acquired intermediate result.
In one embodiment of the present invention, the pilot sequence in step 1 is Ψ ═ Ψ1,Ψ2,…,ΨL]With a length of L, it can be split into two pilot subsequences Ψ with a length of L/21＝[Ψ1,1,Ψ1,2,…,Ψ1,L/2]To Ψ2＝[Ψ2,1,Ψ2,2,…,Ψ2,L/2]And the two pilot frequency subsequences satisfy the relation: Ψ2＝Ψ1ejWhere a predetermined phase difference between two pilot subsequences is indicated.
In one embodiment of the invention, the multi-antenna combining vector a in step 2ijThe calculation formula of (2) is as follows:
Figure BDA0002042830220000021
Figure BDA0002042830220000022
wherein Q (-) is a 1-bit quantization function,
Figure BDA0002042830220000023
for the jth pilot symbol Ψ in the ith pilot subsequencei,jCorresponding channel estimation values, i is 1, 2, j is 1, 2, …, L/2, h is an uplink channel complex vector, and the dimension of the uplink channel complex vector h is N × 1, rhoPIs pilot power, NP,i,jFor the jth pilot symbol Ψ in the ith pilot subsequencei,jThe noise in the pilot transmission phase is reduced,
Figure BDA0002042830220000024
for pilot symbols Ψi,jThe conjugate transpose matrix of (2).
In an embodiment of the present invention, a calculation formula corresponding to the multi-antenna combination in step 3 is:
Figure BDA0002042830220000025
in the formula (I), the compound is shown in the specification,
Figure BDA0002042830220000026
to use the jth pilot symbol Ψ in the ith pilot subsequencei,jFor high-order modulation signal xtResult of the multiple antenna combining, hnFor the nth element, N, in the complex vector h of the uplink channelP,i,j,nIs noise NP,i,jOf (d) (. 1)*For conjugate operation, rhoUTransmission power, w, for transmitting high frequency modulated signals to a terminalt,nFor the phase noise w of data transmissiontThe nth element of (1).
In one embodiment of the invention, the phase difference is preset to be pi/4 in step 1.
In one embodiment of the present invention, the step 3 of calculating the phase of the intermediate result includes setting the phase of the multi-antenna combination result corresponding to the first pilot sub-sequence as a first set of phase results, setting the phase of the multi-antenna combination result corresponding to the second pilot sub-sequence as a second set of phase results, and calculating the g-th phase result (g ═ 1, 2, …, L/2) in the first set of phase results, which sequentially corresponds to the j-th pilot symbol Ψ in the 1 st pilot sub-sequence1,j) And the f-th phase result (f ═ 1, 2, …, L/2) in the second group of phase results, in turn, corresponding to the j-th pilot symbol Ψ in the 2 nd pilot subsequence2,j) The arithmetic mean of (a) is taken as the kth phase of the intermediate result (k is 1, 2, …, L/2).
In one embodiment of the invention, the step 3 of calculating the amplitude of the intermediate result comprises: the amplitude of the multi-antenna combination result corresponding to the first pilot sub-sequence is set as a first set of amplitude results, the amplitude of the multi-antenna combination result corresponding to the second pilot sub-sequence is set as a second set of amplitude results, and the g-th amplitude result (g ═ 1, 2, …,l/2, which in turn corresponds to the jth pilot symbol Ψ in the 1 st pilot sub-sequence1,j) And the f-th amplitude result (f ═ 1, 2, …, L/2 in the second set of amplitude results, which in turn corresponds to the j-th pilot symbol Ψ in the 2 nd pilot subsequence2,j) The arithmetic mean of (a) is taken as the kth amplitude of the intermediate result (k is 1, 2, …, L/2).
In one embodiment of the present invention, the step 3 of calculating the amplitude of the intermediate result includes setting the amplitude of the multi-antenna combination result corresponding to the first pilot sub-sequence as the first set of amplitude results, setting the amplitude of the multi-antenna combination result corresponding to the second pilot sub-sequence as the second set of amplitude results, and calculating the g-th amplitude result (g ═ 1, 2, …, L/2) in the first set of amplitude results, which sequentially corresponds to the j-th pilot symbol Ψ in the 1 st pilot sub-sequence1,j) And the f-th amplitude result (f ═ 1, 2, …, L/2 in the second set of amplitude results, which in turn corresponds to the j-th pilot symbol Ψ in the 2 nd pilot subsequence2,j) The geometric mean of (a) is taken as the kth amplitude of the intermediate result (k is 1, 2, …, L/2).
In an embodiment of the present invention, the calculating, in step 3, a detection result of the high-order modulation signal according to the phase and the amplitude of the obtained intermediate result includes: and carrying out statistical averaging on the obtained intermediate results (the number of the intermediate results is equal to the length of the pilot frequency subsequence), and taking the statistical averaging result as the detection result of the currently transmitted high-order modulation signal.
In one embodiment of the invention, the base station adopts a least square channel estimation method to carry out channel estimation.
In one embodiment of the invention, the base station performs 1-bit digital-to-analog conversion on the received pilot symbols before performing channel estimation.
In another aspect, the present invention provides a mimo system, wherein the mimo system performs signal modulation using a low bit rate quantization method, and performs signal modulation using the method described above when performing high order modulation for low bit rate quantization.
Compared with the prior art, the invention has the advantages that:
on the premise of not increasing extra pilot frequency overhead, the invention designs the pilot frequency sequence, the channel estimation and the signal combination method, obviously reduces the phase error generated when high-order signals in the low-bit quantization massive MIMO system are modulated, improves the precision of actual channel estimation, reduces the demodulation performance loss of high-order phase modulation, and is beneficial to improving the effective throughput.
Drawings
The invention is illustrated and described only by way of example and not by way of limitation in the scope of the invention as set forth in the following drawings, in which:
fig. 1 shows a schematic flow diagram of a method of reducing phase error in low bit quantized high order modulation according to an embodiment of the invention;
FIG. 2 is a simulation diagram illustrating the phase difference between the combined result and the original signal for multiple antennas according to one embodiment of the present invention;
FIG. 3 illustrates a phase error versus simulation graph according to one embodiment of the present invention;
FIG. 4 shows a graph of bit error rate versus simulation after demodulation of a 16PSK signal according to one embodiment of the present invention;
fig. 5 shows a graph of demodulated bit error rates versus simulations for a 64PSK signal in accordance with an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions, design methods, and advantages of the present invention more apparent, the present invention will be further described in detail by specific embodiments with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
As shown in fig. 1, the present invention provides a method for reducing phase error in high order modulation with low bit quantization, which is suitable for data transmission of uplink channel between a terminal and a base station in a large-scale mimo system, wherein the base station is provided with a plurality of antennas, and the terminal is a single antenna, and wherein only one terminal is taken as an exampleObviously, the base station deploys a massive MIMO system, the number of base station antennas is set to be N, and an uplink channel h ∈ C from the terminal to the base stationN×1Is a complex vector with dimension of N × 1, and can be specifically expressed as h-CN (0, I)N) Obedience mean value is 0, covariance matrix is identity matrix INComplex gaussian distribution. The method comprises the following steps:
step 1, a terminal generates and sends a pilot frequency sequence to a base station, the pilot frequency sequence is divided into two pilot frequency subsequences with equal length, a preset phase difference is formed between the two pilot frequency subsequences, and the pilot frequency subsequences at least comprise one pilot frequency symbol. Preferably, the predetermined phase difference is pi/4.
In this step, the pilot sequence is set to Ψ ═ Ψ1,Ψ2,…,ΨL]Which is L in length, can be split into two subsequences Ψ each L/2 in length1＝[Ψ1,1,Ψ1,2,…,Ψ1,L/2]To Ψ2＝[Ψ2,1,Ψ2,2,…,Ψ2,L/2]In the following example, the present invention is described by taking as an example the length L of a pilot sequence being 2, 1-bit quantization, i.e. the pilot sequence can be split into two pilot subsequences Ψ of length 11＝[Ψ1,1]And Ψ2＝[Ψ2,1]The pilot subsequence only includes one pilot symbol, and two pilot symbols are set to be psi in sequence1、Ψ2I.e. Ψ1,1＝Ψ1，Ψ2,1＝Ψ2First pilot symbol
Figure BDA0002042830220000051
Second pilot symbol
Figure BDA0002042830220000052
Or
Figure BDA0002042830220000053
Figure BDA0002042830220000054
That is, in the step 1, the terminal generates two pilot symbols having a phase difference of pi/4, i.e., the specific phase difference is pi/4 at the time of 1-bit quantization and 2-bit rate quantization, combines the two pilot symbols into one pilot sequence, and transmits the pilot sequence to the base station through the uplink channel h.
Since the pilot sequence is interfered by noise during transmission, the noise is set to be NP＝[NP,1,1NP,2,1]Then the signal received by the base station
Figure BDA0002042830220000055
Where ρ isPFor pilot power, Ψ ═ Ψ1Ψ2]。
Step 2, the base station carries out channel estimation according to each pilot frequency symbol in each received pilot frequency subsequence respectively, and generates a multi-antenna merging vector of the pilot frequency subsequence according to the result of each channel estimation;
after receiving the pilot frequency symbol, the base station performs 1-bit digital-to-analog conversion on the received pilot frequency symbol, and performs channel estimation by adopting a least square channel estimation method after the conversion. In this step, the multi-antenna combining with matched filtering is taken as an example for explanation, and the multi-antenna combining vector aijThe calculation formula of (2) is as follows:
Figure BDA0002042830220000056
Figure BDA0002042830220000057
wherein Q (-) is a 1-bit quantization function,
Figure BDA0002042830220000058
for the jth pilot symbol Ψ in the ith pilot subsequencei,jCorresponding channel estimation values, i is 1, 2, j is 1, 2, …, L/2, h is an uplink channel complex vector, and the dimension of the uplink channel complex vector h is N × 1, NP,i,jFor the jth pilot symbol Ψ in the ith pilot subsequencei,jThe noise in the pilot transmission phase is reduced,
Figure BDA0002042830220000061
for pilot symbols Ψi,jThe conjugate transpose matrix of (2).
By the above calculation formula, the first pilot symbol Ψ can be obtained1And a second pilot symbol Ψ2Two multi-antenna combining vectors a1,1And a2,1Wherein, in the step (A),
Figure BDA0002042830220000062
Figure BDA0002042830220000063
and 3, the base station respectively performs multi-antenna combination on the received high-order modulation signals according to each multi-antenna combination vector, calculates an intermediate result according to the result of all multi-antenna combination and a preset phase difference, obtains the phase and amplitude of the intermediate result, and calculates a detection result according to the phase and amplitude of the obtained intermediate result.
In an embodiment of the present invention, a calculation formula corresponding to the multi-antenna combination in step 3 is:
Figure BDA0002042830220000064
in the formula (I), the compound is shown in the specification,
Figure BDA0002042830220000065
using the jth pilot symbol Ψ in the ith pilot subsequence for the current time ti,jFor high-order modulation signal xtResult of the multiple antenna combining, hnFor the nth element, N, in the complex vector h of the uplink channelP,i,j,nIs noise NP,i,jThe nth element of (1) (.)*As a companion matrix, ρUTransmission power, w, for transmitting high frequency modulated signals to a terminalt,nFor the phase noise w of data transmissiontThe nth element of (1).
In step 3, a complex phase obtaining function angle () is used to perform phase extraction on the result of multi-antenna combination corresponding to the two pilot subsequences (pilot symbols), and a function | · | is used to perform amplitude extraction on the result of multi-antenna combination corresponding to the two pilot subsequences (pilot symbols), so as to obtain a phase component and an amplitude component, respectively.
It should be noted that, in the present embodiment, the preset phase difference is pi/4, and the inventor statistically calculates a large amount of data, and when the preset phase difference is pi/4, the phase difference of the multi-antenna combining result calculated based on the first pilot symbol and the multi-antenna combining result calculated based on the second pilot symbol is almost opposite, as shown in fig. 2. Therefore, the inventor believes that the method of calculating the average value can be adopted to calculate the phase and amplitude, that is, the result of calculating the phase and amplitude of the high-order modulation signal according to the result of the multi-antenna combination is:
Figure BDA0002042830220000071
Figure BDA0002042830220000072
preferably, the mean function may determine the amplitude of the high-order modulation signal by using an arithmetic mean value method and a geometric mean value method.
In this embodiment, based on the conventional channel estimation using orthogonal sequences (Zadoff-Chu sequences) as a contrast scheme, phase errors between the technical scheme and the contrast scheme in the present invention are simulated, and the obtained simulation result is shown in fig. 3, and it can be known from fig. 3 that when the pilot lengths are all 2, the maximum value of the phase errors is 4.075 degrees when the channel estimation is performed using the conventional Zadoff-Chu sequences. After the method provided by the invention is used, the maximum value of the phase error can be reduced to 0.175 degrees, and the reduction of the phase error can reach more than 20 times.
The bit error rate simulation curves obtained by demodulating the 16PSK signal and the 64PSK signal respectively by using the above two schemes are shown in fig. 4 and fig. 5. Fig. 4 illustrates the bit error rate comparison after demodulation of 16PSK signals for the conventional method and the proposed method when 1 bit quantization is performed and 1000 antennas are deployed in the base station. As can be seen from fig. 4, when the pilot lengths are all 2, and the ratio of energy per bit to noise power spectral density (EB/N0) is greater than 0dB, the bit error rate can be reduced by using the phase error cancellation scheme proposed by the present invention, especially when EB/N0 is greater than 10dB, compared with the conventional scheme using Zadoff-Chu sequence, the bit error rate can be reduced by more than 10 times. Even when EB/N0 is larger than 15dB, a lower bit error rate can be obtained using the phase error cancellation scheme proposed by the present invention than using a Zadoff-Chu sequence of length 10.
Fig. 5 verifies that the proposed scheme of the present invention can also reduce the bit error rate when 2 bits are quantized, so the method of the present invention is not limited to 1 bit quantization. Fig. 5 illustrates the bit error rate comparison after demodulation of 64PSK signals for the conventional method and the proposed method when 2-bit quantization is performed and 1000 antennas are deployed at the base station. As can be seen from fig. 5, when the pilot lengths are all 2, and the ratio of energy per bit to noise power spectral density (EB/N0) is greater than 0dB, the bit error rate can be reduced by using the phase error cancellation scheme proposed by the present invention.
Although the present invention has been described in detail with the pilot sequence length of 2, the present invention is not limited to the pilot sequence length of 2. When the pilot sequence length is greater than 2, taking length 4 as an example, the pilot sequence is Ψ ═ Ψ1,Ψ2,Ψ3,Ψ4]It can be split into two pilot subsequences Ψ of length 21＝[Ψ1,1，Ψ1,2]To Ψ2＝[Ψ2,1,Ψ2,2]And Ψ2＝Ψ1ejπ/4Or Ψ2＝Ψ1e-jπ/4. The base station respectively bases on each pilot symbol psi in the received pilot subsequence1,1,Ψ1,2,Ψ2,1,Ψ2,2Respectively carry out channel estimation to obtain the channel estimation results of
Figure BDA0002042830220000073
And respectively generating a multi-antenna merging vector a according to the result of each channel estimation11,a12,a21,a22(ii) a The base station respectively carries out multi-antenna combination on the received high-order modulation signals according to each multi-antenna combination vector to obtain multi-antenna combination results
Figure BDA0002042830220000081
With pilot subsequence Ψ1The corresponding multi-antenna combining result is
Figure BDA0002042830220000082
With pilot subsequence Ψ2The corresponding multi-antenna combining result is
Figure BDA0002042830220000083
Namely, it is
Figure BDA0002042830220000084
Is a first set of phase results, has amplitudes that are a first set of amplitude results,
Figure BDA0002042830220000085
is the second set of phase results and has an amplitude that is the second set of amplitude results.
Computing
Figure BDA0002042830220000086
Phase of
Figure BDA0002042830220000087
Is calculated as the first phase of the intermediate result
Figure BDA0002042830220000088
Phase of
Figure BDA0002042830220000089
As the second phase of the intermediate result. Computing
Figure BDA00020428302200000810
Amplitude of and
Figure BDA00020428302200000811
is calculated as the first amplitude of the intermediate result, is calculated as the arithmetic or geometric mean of the amplitudes of
Figure BDA00020428302200000812
Amplitude of and
Figure BDA00020428302200000813
as the second amplitude of the intermediate result, is the arithmetic or geometric mean of the amplitudes of (a). And calculating a statistical average value of the first phase and the second phase, taking the statistical average value as the phase of the intermediate result, calculating a statistical average value of the first amplitude and the second amplitude as the amplitude of the intermediate result, demodulating the currently transmitted high-order modulation signal according to the phase and the amplitude of the intermediate result, and calculating a detection result of the high-order modulation signal.
In summary, the present invention provides a method for reducing phase error in high order modulation with low bit quantization, the method is suitable for data transmission of an uplink channel between a terminal and a base station in a large-scale mimo system, the base station is provided with a plurality of antennas, and the method includes: step 1, a terminal generates and sends a pilot frequency sequence to a base station, wherein the pilot frequency sequence is divided into two pilot frequency subsequences with equal length, a preset phase difference is formed between the two pilot frequency subsequences, and the pilot frequency subsequences at least comprise a pilot frequency symbol; step 2, the base station carries out channel estimation according to each pilot frequency symbol in each received pilot frequency subsequence respectively, and generates a multi-antenna merging vector of the pilot frequency subsequence according to the result of each channel estimation; and 3, the base station respectively performs multi-antenna combination on the received high-order modulation signals according to each multi-antenna combination vector, calculates an intermediate result according to the result of all multi-antenna combination and a preset phase difference, obtains the phase and amplitude of the intermediate result, and calculates a detection result according to the phase and amplitude of the obtained intermediate result. By the technical scheme of the invention, the phase error generated during the modulation of the high-order signal in the low-bit-quantization massive MIMO system is obviously reduced, and the precision of the actual channel estimation is improved.
It should be noted that, although the steps are described in a specific order, the steps are not necessarily performed in the specific order, and in fact, some of the steps may be performed concurrently or even in a changed order as long as the required functions are achieved.
The present invention may be a system, method and/or computer program product. The computer program product may include a computer-readable storage medium having computer-readable program instructions embodied therewith for causing a processor to implement various aspects of the present invention.
The computer readable storage medium may be a tangible device that retains and stores instructions for use by an instruction execution device. The computer readable storage medium may include, for example, but is not limited to, an electronic memory device, a magnetic memory device, an optical memory device, an electromagnetic memory device, a semiconductor memory device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a Static Random Access Memory (SRAM), a portable compact disc read-only memory (CD-ROM), a Digital Versatile Disc (DVD), a memory stick, a floppy disk, a mechanical coding device, such as punch cards or in-groove projection structures having instructions stored thereon, and any suitable combination of the foregoing.
Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims (11)

1. A method for reducing phase error in high order modulation of low bit quantization, the method being suitable for data transmission of an uplink channel between a terminal and a base station in a massive multiple-input multiple-output (mlmo) system with low bit quantization, the base station being provided with a plurality of antennas, the method comprising:
step 1, the terminal generates and sends a pilot frequency sequence to the base station, the pilot frequency sequence is divided into two pilot frequency subsequences with equal length, a preset phase difference is formed between the two pilot frequency subsequences, and the pilot frequency subsequences at least comprise a pilot frequency symbol;
step 2, the base station carries out channel estimation according to each pilot frequency symbol in each received pilot frequency subsequence respectively, and generates a multi-antenna combination vector corresponding to each pilot frequency symbol in each pilot frequency subsequence according to the result of each channel estimation respectively;
and 3, the base station respectively performs multi-antenna combination on the received high-order modulation signals according to each multi-antenna combination vector, calculates an intermediate result according to the result of all multi-antenna combination and the preset phase difference, acquires the phase and amplitude of the intermediate result, and calculates the detection result of the high-order modulation signals according to the acquired phase and amplitude of the intermediate result.
2. Method for reducing phase errors in low bit-quantized higher order modulation according to claim 1, characterised in that in step 2 the multi-antenna combining vector aijThe calculation formula of (2) is as follows:
Figure FDA0002459434350000011
Figure FDA0002459434350000012
wherein Q (-) is a 1-bit quantization function,
Figure FDA0002459434350000013
for the jth pilot symbol Ψ in the ith pilot subsequencei，jCorresponding channel estimation values, i is 1, 2, j is 1, 2, …, L/2, h is an uplink channel complex vector, and the dimension of the uplink channel complex vector h is N × 1, rhoPIs pilot power, NP，i，jFor the jth pilot symbol Ψ in the ith pilot subsequencei，jThe noise in the pilot transmission phase is reduced,
Figure FDA0002459434350000014
for pilot symbols Ψi，jThe conjugate transpose matrix of (2).
3. A method for reducing phase error in low bit-quantized high order modulation according to claim 2, wherein the calculation formula for multi-antenna combining in step 3 is:
Figure FDA0002459434350000015
in the formula (I), the compound is shown in the specification,
Figure FDA0002459434350000016
to use the jth pilot symbol Ψ in the ith pilot subsequencei，jFor high-order modulation signal xtResult of the multiple antenna combining, hnFor the nth element, N, in the complex vector h of the uplink channelP，i，j，nIs noise NP，i，jThe nth element of (1) (.)*For conjugate operation, rhoUTransmission power, w, for transmitting high frequency modulated signals to a terminalt，nFor the phase noise w of data transmissiontThe nth element of (1).
4. A method for reducing phase error in low bit quantized high order modulation according to any of claims 1 to 3 wherein the preset phase difference is pi/4.
5. A method for reducing phase error in low bit quantized higher order modulation according to claim 4 wherein calculating the phase of the intermediate result in step 3 comprises:
setting the phase of the multi-antenna combination result corresponding to a first pilot subsequence as a first group phase result, setting the phase of the multi-antenna combination result corresponding to a second pilot subsequence as a second group phase result, calculating an arithmetic mean value of a g-th phase result in the first group phase result and a f-th phase result in the second group phase result, and recording the arithmetic mean value as a k-th phase of an intermediate result, wherein g is 1, 2, …, L/2, and sequentially corresponds to a j-th pilot symbol psi in a 1-th pilot subsequence1，jF ═ 1, 2, …, L/2, in turn, corresponds to the jth pilot symbol Ψ in the 2 nd pilot subsequence2，j，k＝1，2，…，L/2。
6. A method for reducing phase error in low bit quantized higher order modulation according to claim 5 wherein calculating the amplitude of the intermediate result in step 3 comprises:
setting the amplitude of the multi-antenna combination result corresponding to a first pilot sub-sequence as a first group of amplitude results, setting the amplitude of the multi-antenna combination result corresponding to a second pilot sub-sequence as a second group of amplitude results, calculating the arithmetic mean value of the g-th amplitude result in the first group of amplitude results and the f-th amplitude result in the second group of amplitude results, and recording the arithmetic mean value as the k-th amplitude of the intermediate result.
7. A method for reducing phase error in low bit quantized higher order modulation according to claim 5 wherein calculating the amplitude of the intermediate result in step 3 comprises:
setting the amplitude of the multi-antenna combination result corresponding to a first pilot sub-sequence as a first group of amplitude results, setting the amplitude of the multi-antenna combination result corresponding to a second pilot sub-sequence as a second group of amplitude results, calculating the geometric mean of the g-th amplitude result in the first group of amplitude results and the f-th amplitude result in the second group of amplitude results, and recording the geometric mean as the k-th amplitude of the intermediate result.
8. A method for reducing phase error in low bit quantized higher order modulation according to any of claims 5 to 7 wherein calculating the detection result of the higher order modulation signal from the phase and amplitude of the intermediate result obtained in step 3 comprises:
and carrying out statistical averaging on the obtained intermediate results, and taking the statistical averaging result as the detection result of the currently transmitted high-order modulation signal.
9. Method for reducing phase errors in low bit quantized higher order modulation according to claim 1,
and the base station adopts a least square channel estimation method to carry out the channel estimation.
10. A method for reducing phase error in low bit quantized higher order modulation according to claim 1 wherein said base station performs 1 bit digital to analog conversion on said received pilot symbols prior to performing said channel estimation.
11. A massive mimo system, characterized in that it uses low bit quantization for signal modulation, and when performing high order modulation for low bit quantization, it uses the method of any of claims 1-10 for signal modulation.
CN201910347473.1A 2019-04-28 2019-04-28 Method for reducing phase error in high-order modulation of low bit quantization Active CN110149285B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910347473.1A CN110149285B (en) 2019-04-28 2019-04-28 Method for reducing phase error in high-order modulation of low bit quantization

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910347473.1A CN110149285B (en) 2019-04-28 2019-04-28 Method for reducing phase error in high-order modulation of low bit quantization

Publications (2)

Publication Number Publication Date
CN110149285A CN110149285A (en) 2019-08-20
CN110149285B true CN110149285B (en) 2020-07-31

Family

ID=67593959

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910347473.1A Active CN110149285B (en) 2019-04-28 2019-04-28 Method for reducing phase error in high-order modulation of low bit quantization

Country Status (1)

Country Link
CN (1) CN110149285B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111224765B (en) * 2020-01-08 2021-07-20 中国科学院计算技术研究所 Pilot frequency sequence generation method and corresponding signal transmitting and receiving method and device
CN113242195B (en) * 2021-06-30 2022-06-24 重庆邮电大学 Narrow-band millimeter wave MIMO channel estimation method under low-precision all-digital architecture

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101783781A (en) * 2010-02-05 2010-07-21 华中科技大学 Information transmission method for lowering peak to average power ratio of OFDM system signal
WO2018068208A1 (en) * 2016-10-11 2018-04-19 Telefonaktiebolaget Lm Ericsson (Publ) Methods and apparatuses for spatial pre-processing of signals in a wireless communication system
CN108390836A (en) * 2018-01-10 2018-08-10 南京邮电大学 A kind of extensive mimo system uplink channel estimation method

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8494075B2 (en) * 2010-08-26 2013-07-23 Qualcomm Incorporated Single stream phase tracking during channel estimation in a very high throughput wireless MIMO communication system
US9794036B2 (en) * 2015-03-26 2017-10-17 Facebook, Inc. Optimizations for zero-forcing precoding
EP3119023A1 (en) * 2015-07-16 2017-01-18 Alcatel Lucent Methods for multiplexing and assigning upink reference signals in a radio communication system with a first network node and a second network node
CN106911439B (en) * 2015-12-22 2020-04-14 上海诺基亚贝尔股份有限公司 Pilot signal adaptation method of MIMO system, base station and user equipment
CN108242984B (en) * 2016-12-23 2021-01-15 普天信息技术有限公司 Method for generating pilot frequency sequence of multi-sub-band system
CN108023843A (en) * 2017-12-08 2018-05-11 电子科技大学 The adaptive quantizing channel estimation methods of extensive mimo system based on 1 bit A/D C
CN108365873B (en) * 2018-01-12 2021-03-23 东南大学 Large-scale MIMO self-adaptive transmission method adopting low-precision ADC millimeter waves
CN108880774B (en) * 2018-07-11 2021-01-01 郑州航空工业管理学院 Frequency division duplex multi-user large-scale multi-antenna system and downlink pilot signal length design method thereof
CN109150259B (en) * 2018-09-06 2021-04-27 华北电力大学（保定） Dynamic migration pilot frequency distribution method based on Massive MIMO system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101783781A (en) * 2010-02-05 2010-07-21 华中科技大学 Information transmission method for lowering peak to average power ratio of OFDM system signal
WO2018068208A1 (en) * 2016-10-11 2018-04-19 Telefonaktiebolaget Lm Ericsson (Publ) Methods and apparatuses for spatial pre-processing of signals in a wireless communication system
CN108390836A (en) * 2018-01-10 2018-08-10 南京邮电大学 A kind of extensive mimo system uplink channel estimation method

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Bule Sun;Yiqing Zhou;Lin Tian;Jinglin Shi.Successive Interference Cancellation Based Channel Estimation for Massive MIMO Systems.《 GLOBECOM 2017 - 2017 IEEE Global Communications Conference》.2018,全文. *

Also Published As

Publication number Publication date
CN110149285A (en) 2019-08-20

Similar Documents

Publication Publication Date Title
CN111698182B (en) Time-frequency blocking sparse channel estimation method based on compressed sensing
US8218671B2 (en) Receiving apparatus, receiving method and communication system
US8654910B1 (en) Co-channel interference cancellation with multiple receive antennas for BICM
CN107624235B (en) Apparatus and method for estimating downlink channel in wireless communication system
US9008211B2 (en) Receiving device, receiving method, and receiving program
CN110149285B (en) Method for reducing phase error in high-order modulation of low bit quantization
US11996899B2 (en) Method of discrete digital signal recovery in noisy overloaded wireless communication systems in the presence of hardware impairments
US20060176971A1 (en) Multi input multi output wireless communication reception method and apparatus
CN106941463A (en) A kind of single-bit quantification mimo system channel estimation methods and system
US8347168B2 (en) Multiple-input-multiple-output transmission using non-binary LDPC coding
EP1609265B1 (en) Signal processing apparatus and method
US10530610B2 (en) Method and apparatus for estimating channel in multiple-input multiple-output communication systems exploiting temporal correlations
CN107809399B (en) Multi-antenna millimeter wave channel estimation method for quantized received signals
WO2010103647A1 (en) Mimo reception method
CN112039562B (en) Progressive coding space shift keying method
Seidel et al. Low-complexity 2-coordinates descent for near-optimal MMSE soft-output massive MIMO uplink data detection
Okawa et al. Power-based criteria for signal reconstruction using 1-bit resolution DACs in massive MU-MIMO OFDM downlink
KR102144715B1 (en) Online Clustering Aided Minimum Weighted Hamming Distance Detection for MU-MIMO Systems with Low Resolution ADCs and Apparatus Therefor
CN107248876B (en) Generalized spatial modulation symbol detection method based on sparse Bayesian learning
CN104038317A (en) Blind recognition method for space-frequency coding patterns on basis of feature extraction and diversity technology
CN112953607B (en) Method, medium and equipment for eliminating quantization noise of MIMO-OFDM system
WO2024057817A1 (en) Wireless signal processing system and wireless signal processing method
CN116743219B (en) Symbol-level precoding method and system for non-orthogonal multiple access communication system
US9191155B2 (en) Reception device, reception method, and program
Hasan et al. A Deep Learning-based Efficient Beamspace Estimation Approach in Millimeter-Wave Massive MIMO Systems

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant