UPLINK MU-MIMO METHOD AND SYSTEM

• US 20150264700A1
• Filed: 05/29/2015
• Published: 09/17/2015
• Est. Priority Date: 11/29/2012
• 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: LI, Yue, WANG, Jianguo
• Granted Patent: US 9,554,394 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0404 the mobile station comprising multiple antennas, e.g. to provide uplink diversity
• 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: H04B 7/0634 Antenna weights or vector/matrix coefficients
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/1896 ARQ related signaling
• CPC Class Codes: H04L 25/0391 construction details of matrices
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling

Abstract

The present invention provides an uplink MU-MIMO method. The method includes: sending, by a user equipment, a sounding reference signal to a base station, so that the base station constructs a precoding matrix according to the sounding reference signal, and generates a first scheduling message according to the precoding matrix; receiving the first scheduling message sent by the base station, where the first scheduling message includes a layer mapping rule and the precoding matrix; generating at least one MAC packet data unit MAC PDU according to the first scheduling message, and sending the MAC PDU, so that multiple user equipments exchange the MAC PDUs; generating an uplink signal after the MAC PDU is processed in various layers; and sending, by using an antenna, the uplink signal to the base station. The present invention greatly improves uplink spectral efficiency of a system.

Claims

1. An uplink MU-MIMO method, wherein the method comprises:

receiving, by a base station, sounding reference signals sent by multiple user equipments, wherein the multiple user equipments meet a short-distance transmission condition;

constructing, by the base station, a precoding matrix according to the received sounding reference signals;

generating, by the base station, a first scheduling message according to the precoding matrix;

sending, by the base station, the first scheduling message to the multiple user equipments, so as to schedule at least one user equipment in the multiple user equipments to generate at least one MAC packet data unit (MAC PDU), and exchange the MAC PDUs between the multiple user equipments by using a short-distance transmission technology; and

receiving, by the base station after a preset fixed time, uplink signals sent by the multiple user equipments, wherein the uplink signals are uplink signals generated after the multiple user equipments separately process the MAC PDUs.

2. The method according to claim 1, wherein after the receiving, by the base station after a preset fixed time, uplink signals sent by the multiple user equipments, the method further comprises:

decoding, by the base station, the uplink signals to obtain a codeword, and sending the codeword into a hybrid automatic repeat request process corresponding to the user equipment generating the MAC PDU.

3. The method according to claim 2, wherein after the decoding, by the base station, the uplink signals to obtain a codeword, and sending the codeword into a hybrid automatic repeat request process corresponding to the user equipment generating the MAC PDU, the method further comprises:

checking, by the base station, the codeword, and if the codeword is incorrect, sending a retransmission scheduling message to the user equipment generating the MAC PDU or the multiple user equipments, so as to obtain an uplink retransmission signal uploaded by the user equipment.

4. The method according to claim 3, wherein after the checking, by the base station, the codeword, and if the codeword is incorrect, sending a retransmission scheduling message to the user equipment generating the MAC PDU or the multiple user equipments, the method further comprises:

receiving, by the base station, an uplink retransmission signal sent by one or more user equipments.

5. An uplink MU-MIMO method, wherein the method comprises:

sending, by a user equipment, a sounding reference signal to a base station, so that the base station constructs a precoding matrix according to the sounding reference signal, and generates a first scheduling message according to the precoding matrix;

receiving, by the user equipment, the first scheduling message sent by the base station, wherein the first scheduling message comprises a layer mapping rule and the precoding matrix;

generating, by the user equipment, at least one MAC packet data unit (MAC PDU) according to the first scheduling message, and sending the MAC PDU, so that multiple user equipments exchange the MAC PDUs;

generating, by the user equipment, an uplink signal after the MAC PDU is processed in various layers; and

sending, by the user equipment by using an antenna, the uplink signal to the base station.

6. The method according to claim 5, wherein the generating, by the user equipment, at least one MAC packet data unit MAC PDU according to the first scheduling message, and sending the MAC PDU, so that the multiple user equipments exchange the MAC PDUs comprises:

generating, by the user equipment, at least one MAC PDU, and sending the MAC PDU to other user equipments; and

/or

receiving, by the user equipment, MAC PDUs generated by the other user equipments.

7. The method according to claim 5, wherein the receiving, by the user equipment, the first scheduling message sent by the base station, wherein the first scheduling message comprises a layer mapping rule and the precoding matrix comprises:

performing, by the user equipment, channel coding, rate matching, and modulation on the MAC PDU, so as to generate a corresponding codeword;

performing, by the user equipment, layer mapping of a corresponding layer on the codeword according to the layer mapping rule comprised in the first scheduling message; and

using, by the user equipment according to the precoding matrix comprised in the first scheduling message, a corresponding precoding vector to perform precoding on the layer, so as to obtain the uplink signal.

8. The method according to claim 5, wherein the sending, by the user equipment by using an antenna, the uplink signal to the base station comprises:

if the user equipment generates the MAC PDU, occupying, by the user equipment, a hybrid automatic repeat request process, to send, by using the antenna, the uplink signal to the base station; and

if the user equipment receives all the MAC PDUs, occupying, by the user equipment, the hybrid automatic repeat request process, to send, by using the antenna, the uplink signal to the base station.

9. The method according to claim 5, wherein after the sending, by the user equipment by using an antenna, the uplink signal to the base station, the method further comprises:

receiving, by the user equipment, a retransmission scheduling message sent by the base station; and

sending, by the user equipment, an uplink retransmission signal to the base station according to the retransmission scheduling message.

10. The method according to claim 9, wherein the sending, by the user equipment, an uplink retransmission signal to the base station according to the retransmission scheduling message comprises:

retransmitting, by the user equipment alone, the uplink retransmission signal according to the retransmission scheduling message;

or

coordinating, by the user equipment according to the retransmission scheduling message, with the other user equipments to synchronously retransmit the uplink retransmission signal.

11. A base station, wherein the base station comprises:

a receiver, connected to a processor, and configured to receive sounding reference signals sent by multiple user equipments, wherein the multiple user equipments meet a short-distance transmission condition; and

receive, after a preset fixed time, uplink signals sent by the multiple user equipments, wherein the uplink signals are uplink signals generated after the multiple user equipments separately process a MAC PDUs;

the processor, separately connected to the receiver and a sender, and configured to construct a precoding matrix according to the received sounding reference signals; and

generate a first scheduling message according to the precoding matrix; and

the sender, connected to the processor, and configured to send the first scheduling message to the multiple user equipments, so as to schedule at least one user equipment in the multiple user equipments to generate at least one MAC packet data unit (MAC PDU), and exchange the MAC PDUs between the multiple user equipments by using a short-distance transmission technology.

12. The base station according to claim 11, wherein the processor is further configured to decode the uplink signals to obtain a codeword, and send the codeword into a hybrid automatic repeat request process corresponding to the user equipment generating the MAC PDU.

13. The base station according to claim 12, wherein the processor is further configured to check the codeword;

and

the sender is further configured to;

if the codeword is incorrect, send a retransmission scheduling message to the user equipment generating the MAC PDU, or the multiple user equipments, so as to obtain an uplink retransmission signal.

14. The base station according to claim 13, wherein the receiver is further configured to receive the uplink retransmission signal sent by one or more user equipments.

15. A user equipment, wherein the user equipment comprises:

a sender, connected to a processor, and configured to send a sounding reference signal to a base station, so that the base station constructs a precoding matrix according to the sounding reference signal, and generates a first scheduling message according to the precoding matrix; and

send, by using an antenna, an uplink signal to the base station;

a receiver, connected to the processor, and configured to receive the first scheduling message sent by the base station, wherein the first scheduling message comprises a layer mapping rule and the precoding matrix; and

the processor, separately connected to the sender and the receiver, and configured to generate at least one MAC packet data unit (MAC PDU) according to the first scheduling message, and send the MAC PDU, so that the multiple user equipments exchange the MAC PDUs; and

generate the uplink signal after the MAC PDU is processed in various layers.

16. The user equipment according to claim 15, wherein the processor is further specifically configured to generate at least one MAC PDU;

the sender is further specifically configured to send the MAC PDU to other user equipments; and

the receiver is further specifically configured to receive MAC PDUs generated by the other user equipments.

17. The user equipment according to claim 15, wherein the processor is further specifically configured to perform channel coding, rate matching, and modulation on the MAC PDU, so as to generate a corresponding codeword;

perform layer mapping of a corresponding layer on the codeword according to the layer mapping rule comprised in the first scheduling message; and

perform precoding on the layer according to a corresponding vector in the precoding matrix comprised in the first scheduling message, so as to obtain the uplink signal.

18. The user equipment according to claim 15, wherein the sender is further specifically configured to:

if the MAC PDU is generated, occupy a hybrid automatic repeat request process, to send, by using the antenna, the uplink signal to the base station; and

if all the MAC PDUs are received, occupy the hybrid automatic repeat request process, to send, by using the antenna, the uplink signal to the base station.

19. The user equipment according to claim 15, wherein the receiver is further configured to receive a retransmission scheduling message sent by the base station;

and

the sender is further configured to send an uplink retransmission signal to the base station according to the retransmission scheduling message.