CN108183737A - For the transmission based on gold code in MIMO downlink systems and coding/decoding method - Google Patents
For the transmission based on gold code in MIMO downlink systems and coding/decoding method Download PDFInfo
- Publication number
- CN108183737A CN108183737A CN201810022504.1A CN201810022504A CN108183737A CN 108183737 A CN108183737 A CN 108183737A CN 201810022504 A CN201810022504 A CN 201810022504A CN 108183737 A CN108183737 A CN 108183737A
- Authority
- CN
- China
- Prior art keywords
- matrix
- decoding method
- precoding
- follows
- decoding
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 56
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 title claims abstract description 27
- 239000010931 gold Substances 0.000 title claims abstract description 27
- 229910052737 gold Inorganic materials 0.000 title claims abstract description 27
- 230000005540 biological transmission Effects 0.000 title claims abstract description 23
- 239000011159 matrix material Substances 0.000 claims abstract description 62
- 238000013461 design Methods 0.000 claims abstract description 9
- 239000000654 additive Substances 0.000 claims description 6
- 230000000996 additive effect Effects 0.000 claims description 6
- 238000005562 fading Methods 0.000 claims description 5
- 238000010187 selection method Methods 0.000 claims description 4
- 239000000463 material Substances 0.000 claims description 3
- 238000010606 normalization Methods 0.000 claims description 3
- 239000007787 solid Substances 0.000 claims description 3
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000004891 communication Methods 0.000 description 4
- 230000009977 dual effect Effects 0.000 description 4
- 238000012549 training Methods 0.000 description 4
- 238000004088 simulation Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
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
- H04B7/0456—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
-
- 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
- H04B7/0456—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
- H04B7/0486—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting taking channel rank into account
-
- 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
- H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
- H04B7/0837—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station using pre-detection combining
- H04B7/0842—Weighted combining
- H04B7/0848—Joint weighting
- H04B7/0854—Joint weighting using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
-
- 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
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03891—Spatial equalizers
- H04L25/03898—Spatial equalizers codebook-based design
- H04L25/0391—Spatial equalizers codebook-based design construction details of matrices
-
- 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
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03891—Spatial equalizers
- H04L25/03898—Spatial equalizers codebook-based design
- H04L25/0391—Spatial equalizers codebook-based design construction details of matrices
- H04L25/03917—Spatial equalizers codebook-based design construction details of matrices according to the size of the codebook
-
- 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
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03891—Spatial equalizers
- H04L25/03898—Spatial equalizers codebook-based design
- H04L25/0391—Spatial equalizers codebook-based design construction details of matrices
- H04L25/03923—Spatial equalizers codebook-based design construction details of matrices according to the rank
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Mathematical Physics (AREA)
- Power Engineering (AREA)
- Radio Transmission System (AREA)
Abstract
For the transmission based on gold code in MIMO downlink systems and coding/decoding method, carry out as follows：The first step：Design precoding codebook；Second step：Select pre-encoding codeword；Third walks：Base station sends signal using precoding；4th step：User terminal receives signal matrix Y；5th step：Signal matrix Y is decoded.Beneficial effects of the present invention are as follows：Gold code generally uses ML decodings, and decoding complex degree is quite high.In r=1, its decoding complex degree of the invention of suggesting plans is linear and can realize full rate, i.e., once transmits an information symbol.In r=2, the decoding complex degree that the present invention puies forward combined decoding method can be adjusted by threshold value Λ, can be realized that partial linear decodes, so as to reduce decoding complex degree, and can be reached and approximate performance during ML decodings.At the same time, the transmission plan that the present invention is carried also improves system performance while with low decoding complexity.
Description
Technical Field
The invention belongs to the technical field of wireless communication, particularly relates to the technical field of wireless communication multi-antenna, and particularly relates to an application of a transmission scheme and a decoding method based on gold codes in an MIMO downlink system.
Background
With the demand for information communication anytime and anywhere, Multiple Input Multiple Output (MIMO) technology has become one of the important choices in modern wireless communication. In a MIMO downlink system, a precoding technique is a key technique, which can effectively enhance a desired signal and simultaneously suppress co-channel interference between users, but cannot resist deep fading of a channel. The space-time coding technique can resist deep fading, but cannot effectively suppress interference. The diversity gain and the multiplexing gain can be obtained by combining the two gains, and the system capacity and the spectrum utilization rate can be greatly improved under the condition of not increasing extra bandwidth.
The gold code is a 2 × 2 non-orthogonal space-time block coding (STBC) code that can achieve full rate full diversity, and can achieve maximum coding gain for a MIMO system with two transmit antennas. Compared with other 2 x 2 space-time codes, it can achieve better error rate performance. Also because of these advantages, the gold code has been incorporated into the IEEE802.16(WiMAX) standard. However, since a gold codeword contains 4 independent information symbols, the ML decoding method has high decoding complexity, and few schemes for solving the precoding design problem of the gold code are involved.
Disclosure of Invention
Aiming at the defects of low system performance and high decoding complexity of the existing system based on gold codes, the invention realizes better system performance by utilizing a new precoding design scheme, a precoding code word selection method, a new transmission scheme and a corresponding low-complexity decoding method, and provides a new transmission scheme and a corresponding low-complexity decoding method based on gold codes for an MIMO downlink system.
The invention adopts the following technical scheme:
the gold code-based transmission and decoding method used in the MIMO downlink system is characterized by comprising the following steps:
the first step is as follows: designing a precoding codebook;
the second step is that: selecting a precoding codeword;
the third step: the base station transmits signals by using precoding;
the fourth step: a user side receives a signal matrix Y;
the fifth step: the signal matrix Y is decoded.
The following are preferred embodiments of the present invention.
The first step is as follows: designing precoding codebook
Assuming that the system is single-user, the base station is equipped with MtThe user side is provided with 2 receiving antennas. Design size of L2bPrecoding codebook ofWherein U isiIs MtX r dimensional matrix, and satisfiesHere referred to as r as the rank of the codeword. Code word UiIs defined as
Ui＝Θi-1F0,i＝1,2,…,L
Wherein F0Is MtX r dimensional matrix defined as size MtThe first r columns of the discrete Fourier transform matrix, i.e.
1≤k≤MtAnd l is more than or equal to 1 and less than or equal to Mt
WhereinThe matrix Θ is defined as Mt×MtDiagonal matrix of dimensions, expressed as
Where the parameters on the theta diagonalIs an integer to be determined, an
Codebook design criteria: memory matrixHas an absolute value of dklThat is to say have
Selecting codebook parametersSo thatThe smaller the better, thereby obtaining the optimal precoding codebook
The second step is that: precoding codeword selection
In a data transmission scheme based on finite bit feedback, a base station sends a training sequence, and a user estimates a channel after receiving the training sequence. It is assumed that the user knows the channel information H completely and the feedback channel is error-free, where the matrix H (i.e., channel information) is MtA flat Rayleigh fading channel of x 2 dimension, each element of which is independent of and obeyingThe user can feed back part of the information of H to the base station through a feedback channel of b bits. The specific code selection method is as follows: computingAbsolute value d of determinant (a)iI.e. by
The user selects to take di,i＝1,2,…,2bThe index value of the codeword corresponding to the maximum value in the data is recorded as i0I.e. by
Then handle i0And feeding back to the base station. For the case of r-1 and r-2, the base station has the following two types of precoding:
(1) when r is 1: a precoding codebook isWherein u isiIs MtVector of x 1 dimension. The base station constructs a new precoding matrix as follows:
in the present invention, U is called a dual precoding matrix.
(2) When r is 2: a precoding codebook isWherein U isiIs MtUnitary matrix of x 2 dimensions and satisfiesThe precoding code word selected by the base station end isWhereinIs composed of1, andis composed ofColumn 2.
The third step: base station transmitting signal using precoding
The P × T dimensional data information signal matrix S considered by the present invention is a full rank 2 × 2 gold code that is capable of transmitting 4 complex Quadrature Amplitude Modulation (QAM) symbols with a transmit antenna in 2 time intervals. The structure of gold code is shown as follows
Wherein s is1，s2，s3And s4Is four independent input source symbols taken from an M-QAM constellation S; parameter theta1And theta2Is x2-solid roots of x-1 ═ 0, i.e.Andparameter α1＝1+j(1-θ1) And α2＝1+j(1-θ2) Is used to equalize the transmit power of the transmit antennas. Since the gold code is a linear scatter code, this means that S can be expressed as vec (S) ═ Gs, where vec (·) denotes the vectoring operator and S ═ S1s2s3s4]TIs a symbol vector, G is a generator matrix and GGH＝I4The expression is
For the case of r ═ 1 and r ═ 2, the transmission signal X has the following two types:
(1) when r is 1: the base station transmits a signal X ═ US four times using the dual precoding matrix, and since the number of transmitted symbols is 4, the symbol rate of transmission is 1.
(2) When r is 2: base station transmits signal in two times by using precoding code wordSince the number of transmitted symbols is 4, the transmitted symbol rate is 2.
The fourth step: the user terminal receives the signal matrix Y
Let the channel gains from the transmitting antennas to the user end be recorded as h1And h2I.e. H ═ H1h2]Wherein h is1Is column 1 of H, and H2Column 2 for H.
For the case of r ═ 1 and r ═ 2, the received signal matrix Y has two of the following:
(1) when r is 1: the signals received by the two antennas of the user terminal are respectively marked as Y1And Y2Can be expressed as
Thus, the total received signal of the ue can be obtained as
Where p is the signal-to-noise ratio, factorIs for energy normalization; matrix W1And W2Is 2 x 2-dimensional complex additive white Gaussian noise, each independent and obedient
(2) When r is 2: the signal received by the ue is denoted as Y, which can be expressed as
Where ρ is the signal-to-noise ratio; the matrix W is 2 × 2-dimensional complex additive white Gaussian noise, which is independent and obedient
The fifth step: decoding a signal matrix Y
For the case of r ═ 1 and r ═ 2, there are two decoding methods:
(1) when r is 1:
step 1: will Y1And Y2After being unfolded, the material can be obtained
Wherein y is11，y12，y13And y14And y21，y22，y23And y24Which represents the signals received by the two receiving antennas at the user end in four different time intervals.
Step 2: respectively adding Y1And Y2The received signals are superimposed into a single vector vec (Y)1) And vec (Y)2) The following equation can be obtained:
whereinvec(Y1)＝[y11y12y13y14]T，vec(W1)＝[w11w12w13w14]T，vec(Y2)＝[y21y22y23y24]T，vec(W2)＝[w21w22w23w24]T. But equivalent channelAndthe specific expression is as follows
It is easy to see the equivalent channel matrixAndare all orthogonal so that the ML decoding method can be equivalent to a linear decoding method.
And 3, step 3: order to
Can obtain the product
(2) When r is 2: the invention provides a decoding method which can reduce the decoding complexity and can select proper decoding complexity by adjusting the threshold value, namely a combined ML and MMSE decoding method.
Step 1: the four received signals in Y are stacked into a single vector vec (Y), i.e., vec (Y) ═ Y1y2y3y4]TAnd order
Step 2: computingAnd a threshold value lambda is set for comparison.
And 3, step 3: if it isThe ML decoding method is selected. The decoding method specifically comprises the following steps:
if it isThe MMSE decoding method is selected. The decoding method comprises the following specific steps:
first, let
This matrix is called the MMSE filtering matrix. Then, order
And recordFinally, the MMSE decoding criterion can be described as
The invention has the following beneficial effects:
gold codes generally adopt an ML decoding method, and the decoding complexity is quite high. When r is 1, the decoding complexity of the proposed scheme is linear and full rate can be achieved, i.e. one information symbol is transmitted at a time. When r is 2, the decoding complexity of the joint decoding method provided by the invention can be adjusted through a threshold value Λ, partial linear decoding can be realized, the decoding complexity is reduced, and the performance similar to that of an ML decoding method can be achieved. Meanwhile, the transmission scheme provided by the invention improves the system performance while having low decoding complexity.
Drawings
Fig. 1 is a simulation diagram of the bit error rate of the system of embodiment 1.
Detailed Description
The following describes in detail preferred embodiments of the present invention.
Example 1
The embodiment is used for a gold code-based transmission and decoding method in an MIMO downlink system, and the method comprises the following steps:
the first step is as follows: designing precoding codebook
Assuming that the system is single-user, the base station is equipped with MtThe user side is provided with 2 receiving antennas. Design size of L2bPrecoding codebook ofWherein U isiIs MtX r dimensional matrix, and satisfiesHere referred to as r as the rank of the codeword. Code word UiIs defined as
Ui＝Θi-1F0,i＝1,2,…,L
Wherein F0Is MtX r dimensional matrix defined as size MtThe first r columns of the discrete Fourier transform matrix, i.e.
1≤k≤MtAnd l is more than or equal to 1 and less than or equal to Mt
WhereinThe matrix Θ is defined as Mt×MtDiagonal matrix of dimensions, expressed as
Where the parameters on the theta diagonalIs an integer to be determined, an
Codebook design criteria: memory matrixHas an absolute value of dklThat is to say have
Selecting codebook parametersSo thatThe smaller the better, thereby obtaining the optimal precoding codebook
The second step is that: precoding codeword selection
In the data transmission scheme based on the finite bit feedback, a base station sends a training sequence, and a user receives the training sequenceThe channel is estimated. Assuming that the user knows the channel information H completely and the feedback channel is error free, where the matrix H is MtA flat Rayleigh fading channel of x 2 dimension, each element of which is independent of and obeyingThe user can feed back part of the information of H to the base station through a feedback channel of b bits. The specific code selection method is as follows: computingAbsolute value d of determinant (a)iI.e. by
The user selects to take di,i＝1,2,…,2bThe index value of the codeword corresponding to the maximum value in the data is recorded as i0I.e. by
Then handle i0And feeding back to the base station. For the case of r-1 and r-2, the base station has the following two types of precoding:
(1) when r is 1: a precoding codebook isWherein u isiIs MtVector of x 1 dimension. The base station constructs a new precoding matrix as follows:
in the present invention, U is called a dual precoding matrix.
(2) When r is 2: a precoding codebook isWherein U isiIs MtUnitary matrix of x 2 dimensions and satisfiesThe precoding code word selected by the base station end isWhereinIs composed of1, andis composed ofColumn 2.
The third step: base station transmitting signal using precoding
The P × T dimensional data information signal matrix S considered by the present invention is a full rank 2 × 2 gold code that is capable of transmitting 4 complex Quadrature Amplitude Modulation (QAM) symbols with a transmit antenna in 2 time intervals. The structure of gold code is shown as follows
Wherein s is1，s2，s3And s4Is four independent input source symbols taken from an M-QAM constellation S; parameter theta1And theta2Is x2-solid roots of x-1 ═ 0, i.e.Andparameter α1＝1+j(1-θ1) And α2＝1+j(1-θ2) Is used to equalize the transmit power of the transmit antennas. Since the gold code is a linear scatter code, this means that S can be expressed as vec (S) ═ Gs, where vec (·) denotes the vectoring operator and S ═ S1s2s3s4]TIs a symbol vector, G is a generator matrix and GGH＝I4The expression is
For the case of r ═ 1 and r ═ 2, the transmission signal X has the following two types:
(1) when r is 1: the base station transmits a signal X ═ US four times using the dual precoding matrix, and since the number of transmitted symbols is 4, the symbol rate of transmission is 1.
(2) When r is 2: base station transmits signal in two times by using precoding code wordSince the number of transmitted symbols is 4, the transmitted symbol rate is 2.
The fourth step: the user terminal receives the signal matrix Y
Let the channel gains from the transmitting antennas to the user end be recorded as h1And h2I.e. H ═ H1h2]。
For the case of r ═ 1 and r ═ 2, the received signal matrix Y has two of the following:
(1) when r is 1: the signals received by the two antennas of the user terminal are respectively marked as Y1And Y2Can be expressed as
Thus, the total received signal of the ue can be obtained as
Where p is the signal-to-noise ratio, factorIs for energy normalization; matrix W1And W2Is 2 x 2-dimensional complex additive white Gaussian noise, each independent and obedient
(2) When r is 2: the signal received by the ue is denoted as Y, which can be expressed as
Where ρ is the signal-to-noise ratio; the matrix W is 2 × 2-dimensional complex additive white Gaussian noise, which is independent and obedient
The fifth step: decoding a signal matrix Y
For the case of r ═ 1 and r ═ 2, there are two decoding methods:
(1) when r is 1:
step 1: will Y1And Y2After being unfolded, the material can be obtained
Wherein y is11，y12，y13And y14And y21，y22，y23And y24Which represents the signals received by the two receiving antennas at the user end in four different time intervals.
Step 2: respectively adding Y1And Y2The received signals are superimposed into a single vector vec (Y)1) And vec (Y)2) The following equation can be obtained:
whereinvec(Y1)＝[y11y12y13y14]T，vec(W1)＝[w11w12w13w14]T，vec(Y2)＝[y21y22y23y24]T，vec(W2)＝[w21w22w23w24]T. But equivalent channelAndthe specific expression is as follows
It is easy to see the equivalent channel matrixAndare all orthogonal so that the ML decoding method can be equivalent to a linear decoding method.
And 3, step 3: order to
Can obtain the product
(2) When r is 2: the invention provides a decoding method which can reduce the decoding complexity and can select proper decoding complexity by adjusting the threshold value, namely a combined ML and MMSE decoding method.
Step 1: the four received signals in Y are stacked into a single vector vec (Y), i.e., vec (Y) ═ Y1y2y3y4]TAnd order
Step 2:computingAnd a threshold value lambda is set for comparison.
And 3, step 3: if it isThe ML decoding method is selected. The decoding method specifically comprises the following steps:
if it isThe MMSE decoding method is selected. The decoding method comprises the following specific steps:
first, let
This matrix is called the MMSE filtering matrix. Then, order
And recordFinally, the MMSE decoding criterion can be described as
Suppose the number of antennas at the base station end is Mt4, selecting the feedback bit number as b-4, carrying out Monte-Carol simulation and the iteration number as 106The range of the SNR is 0-14 dB, and it is assumed that a user can obtain complete channel state information.
When r is 1: each element in the transmitted information is uniformly obtained from standard 16-QAM, and the error rate of the transmitted information is converted into a formula of 4-QAMPrecoding codebook parameter value { u1,u2,u3,u4Take {0,1,4,9 }. When r is 2: each element in the transmitted information is uniformly derived from a standard 4-QAM, codebook parameter value { u }1,u2,u3,u4And (5) taking {6,2,5 and 11}, adopting a combined ML and MMSE decoding method, and setting the threshold value Lambda to be 0.8, 5 and 20 respectively, namely the ML decoding accounts for 3.9%, 20% and 47.3% respectively.
Fig. 1 is a simulation diagram of the bit error rate of the system under the above embodiment of the present invention.
It should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to be limiting, and that various changes and modifications to the above embodiments are within the scope of the present invention.
Claims (6)
1. The gold code-based transmission and decoding method used in the MIMO downlink system is characterized by comprising the following steps:
the first step is as follows: designing a precoding codebook;
the second step is that: selecting a precoding codeword;
the third step: the base station transmits signals by using precoding;
the fourth step: a user side receives a signal matrix Y;
the fifth step: the signal matrix Y is decoded.
2. The method as claimed in claim 1, wherein the gold code-based transmission and decoding method for MIMO downlink system comprises:
the first step is as follows: suppose a base station is equipped with MtA transmitting antenna, and a user side is provided with 2 receiving antennas; design size of L2bPrecoding codebook ofWherein, UiIs MtX r dimensional matrix, and satisfies Ui HUi＝Ir(ii) a Referred to herein as r is the rank of the codeword; code word UiIs defined as
Ui＝Θi-1F0,i＝1,2,…,L
Wherein, F0Is MtX r dimensional matrix defined as size MtThe first r columns of the discrete Fourier transform matrix, i.e.
1≤k≤MtAnd l is more than or equal to 1 and less than or equal to Mt
Wherein,the matrix Θ is defined as Mt×MtDiagonal matrix of dimensions, expressed as
Wherein the parametersIs an integer to be determined, an≤L-1；
Codebook design criteria: memory matrix Uk HUlUl HUkHas an absolute value of dklThat is to say have
dkl＝|det(Uk HUlUl HUk)|,1≤k＜l≤L
Selecting codebook parametersSo thatThe smaller the better, thereby obtaining a precoding codebook
3. The method as claimed in claim 2, wherein the gold code-based transmission and decoding method for MIMO downlink system comprises:
the second step is as follows:
it is assumed that the user is fully aware of the channel information H, which is M, and the feedback channel is error-freetA flat Rayleigh fading channel of x 2 dimension, each term being independent and obeyingThe specific code selection method is as follows: calculate Ui HHHHUiAbsolute value d of determinant (a)iI.e. by
di＝|det(Ui HHHHUi)|
The user selects to take di,i＝1,2,…,2bIndex value of code word corresponding to maximum value in the symbol is recorded as i0Then move i0Feeding back to the base station; for the case of r-1 and r-2, the base station has the following two types of precoding:
(1) when r is 1: a precoding codebook isWherein u isiIs MtA dimension vector; the base station constructs a new double precoding matrix as follows:
(2) when r is 2: a precoding codebook isWherein, UiIs MtA unitary matrix of x 2 dimensions; the precoding code word selected by the base station end isWherein,is composed of1, andis composed ofColumn 2.
4. The method as claimed in claim 3, wherein the gold code-based transmission and decoding method for MIMO downlink system comprises:
the third step is as follows:
the data information signal matrix S is a full-rank 2 x 2 gold code, the structure of which is expressed as follows
Wherein s is1，s2，s3And s4Is four unique symbols taken from M-QAM constellation SVertically inputting a source symbol; parameter theta1And theta2Is x2-solid roots of x-1 ═ 0, i.e.Andparameter α1＝1+j(1-θ1) And α2＝1+j(1-θ2) Is used for equalizing the transmitting power of the transmitting antenna;
for the case of r ═ 1 and r ═ 2, the transmission signal X has the following two types:
(1) when r is 1: the base station sends a signal X (US) four times by using a double precoding matrix;
(2) when r is 2: base station transmits signal in two times by using precoding code word
5. The method as claimed in claim 4, wherein the gold code-based transmission and decoding method for MIMO downlink system comprises:
the fourth step is as follows:
let the channel from the transmitting antenna to the user end be H ═ H1h2]Wherein h is1Is column 1 of H, and H2Column 2 for H;
for the case of r ═ 1 and r ═ 2, the received signal matrix Y has two of the following:
(1) when r is 1: the signals received by the two antennas of the user terminal are respectively marked as Y1And Y2Is shown as
Thus, the total received signal of the ue can be obtained as
Where ρ is the signal-to-noise ratio, factorIs for energy normalization; matrix W1And W2Is 2 x 2-dimensional complex additive white Gaussian noise, each independent and obedient
(2) When r is 2: the signal received by the user terminal is marked as Y and expressed as
Wherein the matrix W is 2 × 2-dimensional complex additive white Gaussian noise, each independent and obeying
6. The method as claimed in claim 5, wherein the gold code-based transmission and decoding method for MIMO downlink system comprises:
the fifth step is as follows:
for the case of r ═ 1 and r ═ 2, there are two decoding methods:
(1) when r is 1:
step 1: will Y1And Y2After being unfolded, the material can be obtained
Wherein, y11，y12，y13And y14And y21，y22，y23And y24Representing signals received by two receiving antennas of a user terminal in four different time intervals;
step 2: respectively adding Y1And Y2The received signals are superimposed into a single vector vec (Y)1) And vec (Y)2) The following equation is obtained:
wherein,
vec(Y1)＝[y11y12y13y14]T，vec(W1)＝[w11w12w13w14]T，vec(Y2)＝[y21y22y23y24]T，vec(W2)＝[w21w22w23w24]T(ii) a But equivalent channelAndthe specific expression is as follows
Seeing equivalent channel matrixAndare all orthogonal, so that the ML decoding method is equivalent to the linear decoding method;
and 3, step 3: order to
Can obtain the product
(2) When r is 2: adopting a combined ML and MMSE decoding method;
step 1: y is stacked into a single vector vec (Y), i.e., vec (Y) ═ Y1y2y3y4]TAnd order
Step 2: computingSetting a threshold value lambda to compare with the threshold value lambda;
and 3, step 3: if it isSelecting an ML decoding method, wherein the decoding method specifically comprises the following steps:
if it isThen, an MMSE decoding method is selected, and the specific method of the decoding method is as follows:
first, let
Then, order
And recordFinally, the MMSE decoding criterion is described as
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810022504.1A CN108183737B (en) | 2018-01-10 | 2018-01-10 | Gold code-based transmission and decoding method for MIMO downlink system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810022504.1A CN108183737B (en) | 2018-01-10 | 2018-01-10 | Gold code-based transmission and decoding method for MIMO downlink system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108183737A true CN108183737A (en) | 2018-06-19 |
| CN108183737B CN108183737B (en) | 2020-09-18 |
Family
ID=62550141
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810022504.1A Expired - Fee Related CN108183737B (en) | 2018-01-10 | 2018-01-10 | Gold code-based transmission and decoding method for MIMO downlink system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108183737B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111064500A (en) * | 2019-11-08 | 2020-04-24 | 杭州电子科技大学 | Precoding codebook design method based on channel coding in large-scale MIMO system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103117790A (en) * | 2013-01-17 | 2013-05-22 | 杭州电子科技大学 | Affine projection decoding method of layered algebra space-time codes in downlink multi-user multiple-input-multiple-output system |
| CN105262531A (en) * | 2015-10-27 | 2016-01-20 | 杭州电子科技大学 | Decoding method of large-scale antenna system with user with double antennas |
-
2018
- 2018-01-10 CN CN201810022504.1A patent/CN108183737B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103117790A (en) * | 2013-01-17 | 2013-05-22 | 杭州电子科技大学 | Affine projection decoding method of layered algebra space-time codes in downlink multi-user multiple-input-multiple-output system |
| CN105262531A (en) * | 2015-10-27 | 2016-01-20 | 杭州电子科技大学 | Decoding method of large-scale antenna system with user with double antennas |
Non-Patent Citations (1)
| Title |
|---|
| DAVID J. LOVE ET AL.: "《Limited Feedback Unitary Precoding for Orthogonal Space-Time Block Codes》", 《IEEE TRANSACTIONS ON SIGNAL PROCESSING》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111064500A (en) * | 2019-11-08 | 2020-04-24 | 杭州电子科技大学 | Precoding codebook design method based on channel coding in large-scale MIMO system |
| CN111064500B (en) * | 2019-11-08 | 2021-11-09 | 杭州电子科技大学 | Precoding codebook design method based on channel coding in large-scale MIMO system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108183737B (en) | 2020-09-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7813458B2 (en) | System and method for precoding in a multiple-input multiple-output (MIMO) system | |
| CN107104713B (en) | Method for precoding using block diagonal matrix | |
| US8351544B2 (en) | Method and apparatus for codebook-based feedback in a closed loop wireless communication system | |
| EP2158694B1 (en) | Method and apparatus for feedback in closed loop transmitting | |
| US7949064B2 (en) | Codebook and pre-coder selection for closed-loop mimo | |
| CN101166047B (en) | Multi-antenna communication system transmitting device for channel geometric mean decomposition, receiving device, transmitting method and receiving method | |
| US20070147414A1 (en) | Method of switching transmission modes in IEEE 802.11n MIMO communication systems | |
| CN101232356A (en) | Precoding method, system and apparatus in MIMO system | |
| KR20060130806A (en) | Apparatus and method for transmitting and receiving in close loop mimo system by using codebooks | |
| CN101512929A (en) | Method and apparatus for providing efficient precoding feedback in a mimo wireless communication system | |
| US20050239509A1 (en) | Method and device for detecting vertical bell laboratories layered space-time codes | |
| CN101848071A (en) | Nonlinear decoding method for limited feedback precoding in layered space-time system | |
| CN107707284B (en) | Mixed precoding method based on channel statistic codebook quantization feedback | |
| US8953706B1 (en) | Method for computing sub-stream invariant steering matrices for MIMO beamforming | |
| Salim et al. | Combining training and quantized feedback in multiantenna reciprocal channels | |
| CN108183737B (en) | Gold code-based transmission and decoding method for MIMO downlink system | |
| Ekbatani et al. | Combining beamforming and space-time coding using noisy quantized feedback | |
| Choi et al. | Noncoherent trellis-coded quantization for massive MIMO limited feedback beamforming | |
| US8483305B2 (en) | Apparatus and method for spatial multiplexing in multi input multi output system | |
| KR101100116B1 (en) | Apparatus for transmiter processing precoding using the number of transmiter antenna in open loop communication system and method for the same | |
| CN106936751B (en) | Data transmission method and device | |
| CN113708813A (en) | Multi-user spatial modulation method based on beam forming | |
| CN101272225B (en) | Method and device for implementing full velocity transmission in MIMO system | |
| KR101599532B1 (en) | Method and apparatus for generating a mimo (multiple input multiple output) codebook | |
| Li et al. | Space-Time Code Design for Multiple-Access Channels With Quantized Feedback |
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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20200918 Termination date: 20220110 |