Massive MIMO wireless energy transmission method based on dynamic frame transmission

Patent metadata

Field	Value
Publication number	US-11824604-B2
Application number	US-202217955325-A
Country	US
Kind code	B2
Filing date	Sep 28, 2022
Priority date	Oct 14, 2021
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

The present application discloses a massive MIMO wireless energy transmission method based on dynamic frame transmission. The method comprises the following steps: controlling, by a base station, each antenna to transmit a pilot signal to a user end in a time-sharing mode by using set time-sharing pilot frames; acquiring, by the user end, downlink channel state information from the antennae of the base station to the user end and feeding the downlink channel state information back to the base station; and calculating, by the base station, a precoding matrix based on the downlink channel state information, mapping data from a user layer to an antenna port by using the newly calculated precoding matrix, and performing beam forming calculation with maximization of an energy signal of the user end as a goal.

First claim

What is claimed is:

1. A massive MIMO wireless energy transmission method based on dynamic frame transmission, comprising the following steps:
controlling, by a base station, each antenna to transmit a pilot signal to a user end in a time-sharing mode by using a set time-sharing pilot frame;
acquiring, by the user end, downlink channel state information from the antennae of the base station to the user end and feeding the downlink channel state information back to the base station; and
calculating, by the base station, a precoding matrix based on the downlink channel state information, mapping data from a user layer to an antenna port by using the newly calculated precoding matrix, and performing beam forming calculation with maximization of an energy signal of the user end as a goal.

2. The method according to claim 1 , wherein the time-sharing pilot frame is configured to comprise N LTE radio subframes, and each radio subframe comprises 14 OFDM symbols, wherein the 0 th OFDM symbol is configured as a synchronous frame for a receiving end to detect a starting point of the time-sharing pilot frame; the 1 st OFDM symbol to the N bs OFDM symbol are used for time-sharing pilot transmission of N bs antennae; the N bs +1 th OFDM symbol is null for distinguishing a transmission pilot and a transmission energy; the remaining OFDM symbols are used for energy transmission, and an OFDM symbol content of the transmitted energy is generated using a PN pseudo-random sequence of random numbers.

3. The method according to claim 2 , wherein the base station calculates the precoding matrix by using the following steps:
acquiring a three-dimensional channel state matrix N bs *N ue *N sub fed back by the user end, wherein N bs represents the number of antennae of the base station, N ue represents the number of antennae of the user end, N sub represents the number of subcarriers of the OFDM symbols, and for each subcarrier j, 1≤j≤N sub , a channel state H j is a matrix of N bs *N ue ; and
performing singular value decomposition on each channel state matrix H j to obtain a right singular matrix V j , taking a first column of each V j to obtain a column vector {right arrow over (v j )} with a dimension of N bs , combining the column vectors {right arrow over (v j )} corresponding to all subcarriers to obtain a precoding matrix W with a dimension of N bs *N sub , and then applying, by the base station, the precoding matrix W to a signal to be transmitted to implement a precoding process.

4. The method according to claim 2 , wherein a synchronous symbol of the synchronous frame adopts a direct current square wave.

5. The method according to claim 4 , wherein the receiving end detects the starting point of the time-sharing pilot frame using a sliding window method, comprises the following steps:
at the receiving end, storing continuously-received signals in a buffer area, wherein the number of sampling points of the signals stored in the buffer area at most is marked as N t ;
setting a size of a sampling point of a direct current synchronous signal as N s and a size of a sliding window as S for a section of signals a received in the buffer area, and reversely sliding the sliding window from a tail part to a head part of the buffer area, wherein the size of the sliding window meets a constraint condition of 0<S≤N s ;
while the sliding window slides reversely, calculating an average value V k of signal amplitude values within the window as follows:

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wherein 0≤k≤N t −N t −N s and k is a starting position of the sliding window in the buffer area; and
setting a floating threshold value ρ, and when a difference value between the sampling point within the window and the average amplitude value within the window does not exceed the floating threshold value ρ, confirming that a synchronous symbol is positioned and expressed as follows:

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k

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Assignees

• Univ Shenzhen

Inventors

• Che Yueling
• Li Yishen
• Li Liangzhu
• Luo Sheng
• Wu Kaishun

Classifications

• H04B7/0456 Primary

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

• H04L27/2602

  Signal structure · CPC title

• H04L27/2613 Primary

  Structure of the reference signals · CPC title

• Y02D30/70

  in wireless communication networks · CPC title

• H04B7/0413

  MIMO systems · CPC title