Methods for sending and receiving synchronization signals and signals subjected to perfect omnidirectional pre-coding in large-scale MIMO system

Patent metadata

Field	Value
Publication number	US-10998968-B2
Application number	US-201616066051-A
Country	US
Kind code	B2
Filing date	Jul 4, 2016
Priority date	Jun 21, 2016
Publication date	May 4, 2021
Grant date	May 4, 2021

Abstract

An EnodeB or a transmitting device intermittently generates synchronization signals, and then performs perfect omnidirectional pre-coding processing on the synchronization signals; the synchronization signals after perfect omnidirectional pre-coding processing pass through a transmission channel and are then received by a mobile terminal or a receiving device, and the mobile terminal or the receiving device uses the received synchronization signals and local replicas of the synchronization signals for receiving and synchronization processing. An EnodeB or a transmitting device generates vector signals via low-dimensional space-time coding, and then performs perfect omnidirectional pre-coding processing on the vector signals; the transmitted signals after perfect omnidirectional pre-coding processing pass through a transmission channel and are then received by a mobile terminal or a receiving device, and the mobile terminal or the receiving device uses the received signals for signal receiving processing.

First claim

What is claimed is:

1. A method of realizing perfect omnidirectional pre-coded synchronization signal transmission in a large-scale MIMO system, wherein an EnodeB or a transmitting device intermittently generates K×L synchronization signals, then conducts perfect omnidirectional pre-coding processing on the synchronization signals, and conducts premultiplication on the synchronization signals by an M×K perfect omnidirectional pre-coding matrix W to obtain M×L signals as digital baseband signals transmitted by an antenna array, wherein K is the dimension of the synchronization signals, 2≤K<M, M is the number of the EnodeB antennas, and L is the length of the synchronization signals in one transmitting period;
wherein the perfect omnidirectional pre-coding matrix W is obtained through the following method: firstly, a perfect omnidirectional pre-coding matrix W′ with a dimension of

M
K

×
K

is constructed, and then K-times zero insertion processing is conducted to each column of the perfect omnidirectional pre-coding matrix W′ to obtain the perfect omnidirectional pre-coding matrix W, and each row of the perfect omnidirectional pre-coding matrix W only has one nonzero element.

2. The method of realizing perfect omnidirectional pre-coded synchronization signal transmitting in a large-scale MIMO system according to claim 1 , wherein the perfect omnidirectional pre-coding matrix W satisfies the following design criteria:
(1) the power of the transmitted signals is the same in each spatial direction to guarantee perfect omnidirectional coverage; and
(2) the power of the transmitted signals on each antenna is the same, and the power efficiency of each radio frequency channel and the antenna array is maximized.

3. The method of realizing perfect omnidirectional pre-coded synchronization signal transmitting in a large-scale MIMO system according to claim 1 , wherein the perfect omnidirectional pre-coding matrix W meets the following conditions:
(1) the sum of the squared absolute values of the discrete time Fourier transform of an M-point sequence in each column of the perfect omnidirectional pre-coding matrix W is a constant;
(2) all the row vectors of the perfect omnidirectional pre-coding matrix W have the same 2-norm; and
(3) all the column vectors of the perfect omnidirectional pre-coding matrix W have the same 2-norm and are mutually orthogonal.

4. The method of realizing perfect omnidirectional pre-coded synchronization signal transmitting in a large-scale MIMO system according to claim 1 , wherein the perfect omnidirectional pre-coding matrix W is composed of k sequences in a multiphase complementary orthogonal sequence set, and the multiphase complementary orthogonal sequence set comprises K sequences with a length of M.

5. The method of realizing perfect omnidirectional pre-coded synchronous signal transmitting in a large-scale MIMO system according to claim 4 , wherein when K=2, two column sequences in the multiphase complementary orthogonal sequence set constitute a Golay sequence pair.

6. The method of realizing perfect omnidirectional pre-coded synchronization signal transmitting in a large-scale MIMO system according to claim 1 , wherein the perfect omnidirectional pre-coding matrix W is obtained through the following method: post-multiplication is conducted to a perfect omnidirectional pre-coding matrix W 0 by a K×K unitary matrix U to obtain the M×K perfect omnidirectional pre-coding matrix W.

7. A method of realizing perfect omnidirectional pre-coded synchronization signal receiving in a large-scale MIMO system, wherein synchronization signals after perfect omnidirectional pre-coding processing pass through a transmission channel and are then received by a mobile terminal or a receiving device, and the mobile terminal or the receiving device uses the received synchronization signals and local replicas of the synchronization signals for receiving and synchronization processing;
wherein the perfect omnidirectional pre-coding matrix W is obtained through the following method: firstly, a perfect omnidirectional pre-coding matrix W′ with a dimension of

M
K

×
K

is constructed, and then K-times zero insertion processing is conducted to each column of the perfect omnidirectional pre-coding matrix W′ to obtain the perfect omnidirectional pre-coding matrix W, and each row of the perfect omnidirectional pre-coding matrix W only has one nonzero element.

8. The method of realizing perfect omnidirectional pre-coded synchronization signal receiving in a large-scale MIMO system according to claim 7 , wherein the process that the mobile terminal or the receiving device uses the received synchronization signals and the local replicas of the synchronous signals for receiving and synchronization processing comprises the following steps of:
S 1 : conducting a cross-correlation operation to synchronization signals and local replicas of the synchronization signals received from timing position θ by the mobile terminal or the receiving device, and obtaining the energy;
S 2 : combining the energy corresponding to a plurality of delayed paths to obtain the total energy; and
S 3 : comparing the total energy with a threshold: if the total energy is greater than the threshold, judging that the timing position θ is aligned; otherwise, judging that the timing position θ is not aligned, and changing the locating position θ, and then returning to step S 1 .

Assignees

• Univ Southeast

Inventors

• Gao Xiqi
• Meng Xin

Classifications

• H04B7/1555

  Selecting relay station antenna mode, e.g. selecting omnidirectional -, directional beams, selecting polarizations · CPC title

• H04B7/0413 Primary

  MIMO systems · CPC title

• H04B7/0456 Primary

  Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting · CPC title

• H04B7/0426

  Power distribution · CPC title

• H04B7/2678 Primary

  Time synchronisation · CPC title