Transmission of channel state information in a wireless communication system

Patent metadata

Field	Value
Publication number	US-9210710-B2
Application number	US-201414153426-A
Country	US
Kind code	B2
Filing date	Jan 13, 2014
Priority date	Jul 13, 2011
Publication date	Dec 8, 2015
Grant date	Dec 8, 2015

Abstract

A wireless communication system includes at least one transmit node having at least two transmit antenna ports, and at least one receive node having at least one receive antenna port. User information is transmitted between the at least two transmit antenna ports and the at least one receive antenna port on a radio propagation channel. A reconstructed channel state information (R-CSI) for a reconstructed radio propagation channel is computed. The reconstructed radio propagation channel is obtained as an estimated radio propagation channel compensated by a function of an estimated signal power imbalance between the at least two transmit antenna ports. And an indicative of the estimated signal power imbalance and the R-CSI is sent to the at least one transmit node.

First claim

The invention claimed is:

1. A method of channel state information (CSI) transmission in a wireless communication system, the wireless communication system comprising at least one transmit node having at least two transmit antenna ports, and at least one receive node having at least one receive antenna port, transmission of user information between the at least two transmit antenna ports and the at least one receive antenna port being performed on a radio propagation channel, the method comprising:
computing a reconstructed channel state information (R-CSI) for a reconstructed radio propagation channel, the reconstructed radio propagation channel being obtained as an estimated radio propagation channel compensated by a function of an estimated signal power imbalance between the at least two transmit antenna ports; and
sending an indicative of the estimated signal power imbalance and the R-CSI to the at least one transmit node.

2. The method according to claim 1 , further comprising:
measuring reference signals received from the at least two transmit antenna ports, and
estimating the signal power imbalance based on measurement of the reference signals.

3. The method according to claim 2 , wherein the step of estimating is triggered by signalling information from the at least one transmit node to the at least one receive node.

4. The method according to claim 3 , wherein the signalling information is signalled dynamically or semi-statically.

5. The method according to claim 1 , wherein the estimated signal power imbalance is received signal power associated with each of the at least two transmit antenna ports measured at the at least one receive antenna port.

6. The method according to claim 1 , wherein the estimated signal power imbalance is a ratio of a received signal power associated with a predetermined reference transmit antenna port to a received signal power associated with remaining transmit antenna ports measured at the at least one receive antenna port.

7. The method according to claim 1 , wherein the R-CSI comprises at least one of the following: a reconstructed transmission rank, a reconstructed precoding matrix indicator (R-PMI), and a reconstructed channel quality indicator (R-CQI).

8. The method according to claim 1 , wherein the indicative of the estimated signal power imbalance is used for adjusting transmit power for each of the at least two transmit antenna ports.

9. The method according to claim 8 , wherein the adjusting of transmit power involves: increasing or decreasing transmit power so as to fully or partially compensating for the estimated signal power imbalance.

10. The method according to claim 1 , further comprising:
determining a precoding matrix based on the R-CSI, and
using the precoding matrix for transmission of the user information.

11. The method according to claim 1 , wherein the reconstructed radio propagation channel H′ eff is defined as:

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Assignees

• Huawei Tech Co Ltd

Inventors

• Robert Safavi Anahid
• Popovic Branislav

Classifications

• H04B7/063 Primary

  Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection · CPC title

• H04B7/0632

  Channel quality parameters, e.g. channel quality indicator [CQI] · CPC title

• H04B1/52

  Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa · CPC title

• H04W52/244

  Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI] · CPC title

• H04W72/0473 Primary

  the resource being transmission power · CPC title