Code division multiple access transmission antenna weighting

• US 7,684,469 B2
• Filed: 12/06/2006
• Issued: 03/23/2010
• Est. Priority Date: 09/10/1999
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Mesecher, David K
• Primary Examiner(s): Ghebretinsae; Temesghen
• Application Number:
  US11/567,498
• Publication Number:
  US 20070091985A1
• Time in Patent Office: 1,203 Days
• Field of Search: 375/130, 375/147, 375/219, 375/267, 375/347, 370/335, 370/342, 455/69, 455/67.1
• US Class Current: 375/147
• CPC Class Codes: H04B 1/712 Weighting of fingers for combining, e.g. amplitude control or phase rotation using an inner loop
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04B 7/0613 using simultaneous transmission H04B7/0686 takes precedence
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04B 7/0634 Antenna weights or vector/matrix coefficients
• CPC Class Codes: H04B 7/0678 using different spreading codes between antennas code allocation H04J13/16
• CPC Class Codes: H04B 7/0845 per branch equalization, e.g. by an FIR-filter or RAKE receiver per antenna branch rake receivers as such H04B1/7115
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
• CPC Class Codes: H04B 7/0857 using maximum ratio combining techniques, e.g. signal-to- interference ratio [SIR], received signal strenght indication [RSS]
• CPC Class Codes: H04B 7/0891 Space-time diversity rake receivers H04B1/7115; space-time decoding H04L1/0631
• CPC Class Codes: H04J 13/0003 Code application, i.e. aspects relating to how codes are applied to form multiplexed channels

Abstract

A code division multiple access communication system has a base station with a plurality of transmitting antennas. From each transmitting antenna of the base station, a pilot signal is transmitted having a different chip sequence than the other transmitting antenna. At a user equipment, the transmitted pilot signals are received from each transmitting antenna. A weight adjustment is derived in response to the received transmitted pilot signals. The user equipment transmits the weight adjustment to the base station. The transmitted weight adjustment is received from the user equipment. A data signal is processed to produce a plurality of versions of the data signal. At least a portion of each processed data signal has a different chip sequence than the other processed data signal version. At least one processed data signal version is weighted by a weight value adjusted in response to the received transmitted weight adjustment. From each transmitting antenna, a different one of the data signal versions is transmitted and the transmitted data signal versions are received at the user equipment.

Claims

1. A method for use in a code division multiple access user equipment, the method comprising:

receiving a first continuous pilot signal from a first transmitting antenna of a base station;

receiving a second continuous pilot signal from a second transmitting antenna of the base station, wherein the first continuous pilot signal and the second continuous pilot signal have a different chip sequence;

receiving a data signal comprising two antenna specific chip sequences, wherein each of the antenna specific chip sequences are associated with the respective transmission antenna and the first and second pilot signals have a different channel code than the data signal;

deriving preferred weights in response to the received first and second continuous pilot signals; and

combining a data bit associated with the first antenna with a corresponding data bit associated with the second antenna using the preferred weights.

2. The method of claim 1 further comprising weighting the data bit associated with the first antenna with the preferred weights derived from the first pilot signal.

3. The method of claim 1 further comprising weighting the data bit associated with the second antenna with preferred weights derived from the second pilot signal.

4. The method of claim 3 wherein the preferred weights are derived using a least mean square algorithm.

5. The method of claim 1 further comprising filtering the received first and second continuous pilot signals wherein the preferred weights are derived from the filtered received first and second pilot signals.

6. The method of claim 1 wherein the received first and second data signal are distinguished by the portion of the first and second data signal having the different chip sequence.

7. A code division multiple access user equipment, the user equipment comprising:

a receiving circuit configured to receive a plurality of continuous pilot signals, each continuous pilot signal having a different chip sequence than others of the plurality of continuous pilot signals;

a weight calculation device configured to derive preferred weights in response to the received pilot signals;

the receiving circuit configured to receive a plurality of data signals, at least a portion of each data signal has a different antenna specific chip sequence than others of the plurality of data signals, the receiving circuit configured to filter the received data signals to recover data; and

circuitry configured to combine a data bit associated with a first antenna specific chip sequence with a corresponding data bit associated with a second antenna specific chip sequence using the preferred weight.

8. The user equipment of claim 7 further comprising:

circuitry configured to weight the data bit associated with the first antenna with the preferred weights derived from the first pilot signal.

9. The user equipment of claim 7 further comprising circuitry configured to weight the data bit associated with the second antenna with preferred weights derived from the second pilot signal.

10. The user equipment of claim 7 wherein the plurality of pilot signals and the plurality of data signals are configured to be received from a same base station.

11. The user equipment of claim 7 wherein the preferred weights are derived using an adaptive algorithm.

12. The user equipment of claim 11 wherein the adaptive algorithm is a least mean square algorithm.

13. The user equipment of claim 7 wherein the receiving circuit is configured to filter the received continuous pilot signals;

wherein the weight adjustment device is configure to derive the preferred weights from the filtered received continuous pilot signals.

14. The user equipment of claim 7 wherein the receiving circuit is configured to distinguish the received data signal versions using the at least the portion of each processed data signal having the different chip sequence.