Pilot signal generation method and apparatus

• US 10,404,435 B2
• Filed: 05/24/2017
• Issued: 09/03/2019
• Est. Priority Date: 11/25/2014
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Qiu, Jing, Jia, Ming
• Primary Examiner(s): Perez, James M
• Application Number:
  US15/603,626
• Publication Number:
  US 20170257194A1
• Time in Patent Office: 832 Days
• Field of Search: 375259-285, 375295-296
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04L 1/00 Arrangements for detecting or preventing errors in the information received correcting synchronisation H04L7/00
• CPC Class Codes: H04L 25/0202 Channel estimation
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 5/0016 Time-frequency-code
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal

Abstract

Embodiments of the present invention provide a pilot signal generation method and apparatus, so as to implement sharing of one pilot by multiple UEs when it is ensured that each of the multiple UEs can correctly obtain a data stream, thereby reducing pilot overheads. The method includes: determining a first pilot signal shared by multiple UEs, where the multiple UEs are multiple UEs transmitting data streams on a same time-frequency resource; determining a pilot precoding vector of first UE and a data stream receiving gain of the first UE according to current downlink channel information of the multiple UEs, where the first UE is one of the multiple UEs; and generating, according to the first pilot signal, the data stream receiving gain of the first UE, and the pilot precoding vector of the first UE, a second pilot signal that is to be sent to the first UE.

Claims

1. A method of pilot signal generation, comprising:

determining a first pilot signal shared by multiple user equipments (UEs), wherein the multiple UEs are multiple UEs transmitting data streams on a same time-frequency resource;

obtaining current downlink channel information of the multiple UEs;

determining a pilot precoding vector of a first UE and a data stream receiving gain of the first UE according to the current downlink channel information of the multiple UEs, wherein the first UE is one of the multiple UEs, the determining a pilot precoding vector of first UE and a data stream receiving gain of the first UE according to the current downlink channel information of the multiple UEs comprising;

determining a data precoding vector of the first UE according to the current downlink channel information of the multiple UEs;

determining the receive equalization vector of the first UE according to the current downlink channel information of the first UE and the data precoding vector of the first UE;

determining the pilot precoding vector of the first UE according to the current downlink channel information of the multiple UEs and the receive equalization vector of the first UE; and

determining the data stream receiving gain of the first UE according to the current downlink channel information of the first UE, the receive equalization vector of the first UE, and the data precoding vector of the first UE; and

generating, according to the first pilot signal, the data stream receiving gain of the first UE, and the pilot precoding vector of the first UE, a second pilot signal that is to be sent to the first UE, wherein the pilot precoding vector of the first UE satisfies the following conditions;

a product of the pilot precoding vector of the first UE and the current downlink channel information of each of UEs other than the first UE in the multiple UEs is zero; and

a product of the pilot precoding vector of the first UE and the current downlink channel information of the first UE is a receive equalization vector of the first UE.

2. The method according to claim 1, wherein the determining the pilot precoding vector of the first UE according to the current downlink channel information of the multiple UEs and the receive equalization vector of the first UE comprises:

determining null space of a set of channel information of all the other UEs according to the current downlink channel information of all the other UEs; and

determining the pilot precoding vector of the first UE according to the receive equalization vector of the first UE, the current downlink channel information of the first UE, and the null space of the set of the channel information of all the other UEs.

3. The method according to claim 1, wherein after the generating, according to the first pilot signal, the data stream receiving gain of the first UE, and the pilot precoding vector of the first UE, a second pilot signal that is to be sent to the first UE, the method further comprises:

sending the second pilot signal to the first UE by using a current downlink channel of the first UE.

4. A pilot signal generation apparatus, comprising:

a memory to store instructions; and

a processor to execute the instructions to cause the pilot signal generation apparatus to;

determine a first pilot signal shared by multiple user equipments (UEs), wherein the multiple UEs are multiple UEs transmitting data streams on a same time-frequency resource;

obtain current downlink channel information of the multiple UEs;

determine a pilot precoding vector of first UE and a data stream receiving gain of the first UE according to the current downlink channel information of the multiple UEs, wherein the first UE is one of the multiple UEs, comprising;

determine a data precoding vector of the first UE according to the current downlink channel information of the multiple UEs obtained by the pilot signal generation apparatus;

determine the receive equalization vector of the first UE according to the current downlink channel information of the first UE and the data precoding vector of the first UE;

determine the pilot precoding vector of the first UE according to the current downlink channel information of the multiple UEs and the receive equalization vector of the first UE; and

determine the data stream receiving gain of the first UE according to the current downlink channel information of the first UE, the receive equalization vector of the first UE, and the data preceding vector of the first UE; and

generate, according to the first pilot signal, the data stream receiving gain of the first UE, and the pilot precoding vector of the first UE that are determined by the determining unit, a second pilot signal that is to be sent to the first UE, wherein the pilot precoding vector of the first UE that is determined by the determining unit satisfies the following conditions;

a product of the pilot precoding vector of the first UE and the current downlink channel information of each of UEs other than the first UE in the multiple UEs is zero; and

a product of the pilot precoding vector of the first UE and the current downlink channel information of the first UE is a receive equalization vector of the first UE.

5. The pilot signal generation apparatus according to claim 4, wherein

the processor further executes the instructions to configure the pilot signal generation apparatus to:

determine null space of a set of channel information of all the other UEs according to the current downlink channel information of all the other UEs; and

determine the pilot precoding vector of the first UE according to the receive equalization vector of the first UE, the current downlink channel information of the first UE, and the null space of the set of the channel information of all the other UEs.

6. The pilot signal generation apparatus according to claim 4, wherein the processor further executes the instructions to configure the generation apparatus

to configure the pilot signal generation apparatus to send, after the generation pilot signal apparatus generates the second pilot signal, the second pilot signal generated by the generation pilot signal apparatus to the first UE by using a current downlink channel of the first UE.

7. A base station, comprising:

a processor, configured to;

determine a first pilot signal shared by multiple user equipments (UEs), wherein the multiple UEs are multiple UEs transmitting data streams on a same time-frequency resource;

obtain current downlink channel information of the multiple UEs;

determine a data precoding vector of the first UE according to the current downlink channel information of the multiple UEs;

determine a pilot precoding vector of first UE and a data stream receiving gain of the first UE according to the current downlink channel information of the multiple UEs, wherein the first UE is one of the multiple UEs, comprising;

determine the receive equalization vector of the first UE according to the current downlink channel information of the first UE and the data precoding vectorof the first UE;

determine the pilot precoding vector of the first UE according to the current downlink channel information of the multiple UEs and the receive equalization vector of the first UE; and

determine the data stream receiving gain of the first UE according to the current downlink channel information of the first UE, the receive equalization vector of the first UE, and the data precoding vector of the first UE; and

generate, according to the first pilot signal, the data stream receiving gain of the first UE, and the pilot precoding vector of the first UE, a second pilot signal that is to be sent to the first UE, wherein the pilot precoding vector of the first UE that is determined by the processor satisfies the following conditions;

a product of the pilot precoding vector of the first UE and the current downlink channel information of each of UEs other than the first UE in the multiple UEs is zero; and

a product of the pilot precoding vector of the first UE and the current downlink channel information of the first UE is a receive equalization vector of the first UE.

8. The base station according to claim 7, wherein

the processor is configured to:

determine null space of a set of channel information of all the other UEs according to the current downlink channel information of all the other UEs; and

determine the pilot precoding vector of the first UE according to the receive equalization vector of the first UE, the current downlink channel information of the first UE, and the null space of the set of the channel information of all the other UEs.

9. The base station according to claim 7, wherein the base station further comprises a transceiver, wherein

the transceiver is configured to send, after the processor generates the second pilot signal, the second pilot signal generated by the processor to the first UE by using a current downlink channel of the first UE.