System and method for channel estimation in a delay diversity wireless communication system

• US 9,001,774 B2
• Filed: 11/12/2013
• Issued: 04/07/2015
• Est. Priority Date: 04/21/2005
• Status: Active Grant

• Current Assignee: Unwired Planet International Limited (Brevet Capital)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Khan, Farooq
• Primary Examiner(s): TRAN, CONGVAN
• Application Number:
  US14/078,204
• Publication Number:
  US 20140072061A1
• Time in Patent Office: 511 Days
• Field of Search: 370/328, 370/329, 370/332, 370/338, 370/343, 370/203, 370/208, 370/210, 370/292, 370/480, 370/491, 370/498, 370/500, 375/260, 375/267, 375/299
• US Class Current: 370/329
• CPC Class Codes: H04B 7/0671 using different delays between antennas
• CPC Class Codes: H04B 7/0684 using different training sequences per antenna
• CPC Class Codes: H04B 7/12 Frequency diversity
• CPC Class Codes: H04L 25/022 of frequency response
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 25/03955 in combination with downlink estimations, e.g. downlink path losses
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/261 Details of reference signals
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver

Abstract

A method of controlling downlink transmissions to a subscriber station capable of communicating with a base station of an orthogonal frequency division multiplexing (OFDM) network. The method comprises the steps of: receiving a first pilot signal from a first base station antenna; receiving a second pilot signal from a second base station antenna; and estimating the channel between the base station and subscriber station based on the received first and second pilot signals. The method also comprises determining a set of OFDM symbol processing parameters based on the step of estimating the channel and transmitting the OFDM symbol processing parameters to the base station. The base station uses the OFDM symbol processing parameters to control the relative gains and the relative delays of OFDM symbols transmitted from the first and second antennas.

Claims

1. A method, comprising:

receiving an uplink signal;

determining a processing parameter for transmission of data on two antenna ports, the processing parameter including at least one of a time delay, a phase rotation and a gain based on the received uplink signal;

transmitting a first pilot and a second pilot; and

transmitting a first data symbol and a second data symbol on two antenna ports, at least one of the first data symbol and the second data symbol being processed based on the processing parameter.

2. The method of claim 1, wherein the first pilot and the second pilot are generated independently of the processing parameter, and wherein the processing parameter is a symbol processing parameter.

3. The method of claim 1, wherein the processing parameter is determined on a user-by-user basis.

4. The method of claim 1, wherein the time delay is in a time domain and the phase rotation is in a frequency domain.

5. The method of claim 1, wherein the uplink signal comprises at least one of an orthogonal frequency division multiplexing (OFDM) symbol processing parameter, an uplink pilot, and a preamble.

6. A method, comprising:

receiving a processing parameter for transmission of data on two antenna ports, the processing parameter including at least one of a time delay, a phase rotation and a gain determined based on a received uplink signal;

receiving a first pilot, a second pilot, a first data symbol and a second data symbol transmitted on the two antenna ports; and

demodulating the first data symbol and the second data symbol based on the processing parameter, the first pilot and the second pilot.

7. The method of claim 6, wherein the first pilot and the second pilot are generated independently of the symbol processing parameter.

8. The method of claim 6, wherein the processing parameter is determined on a user-by-user basis.

9. The method of claim 6, wherein the time delay is in a time domain and the phase rotation is in a frequency domain.

10. The method of claim 6, wherein the demodulating further comprises:

estimating a channel using the first pilot, the second pilot and the processing parameter; and

demodulating the first and second data based on the estimated channel.