CODE DIVISION MULTIPLE ACCESS TRANSMISSION ANTENNA WEIGHTING

• US 20070091985A1
• Filed: 12/06/2006
• Published: 04/26/2007
• Est. Priority Date: 09/10/1999
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Mesecher, David
• Granted Patent: US 7,684,469 B2
• Time in Patent Office: Days
• US Class Current: 375/141
• 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 communication system having a base station with a plurality of transmitting antennas, the method comprising:

transmitting from each transmitting antenna of the base station, a pilot signal having a different chip sequence than the other transmitting antenna;

receiving at a user equipment the transmitted pilot signals from each transmitting antenna;

deriving a weight adjustment in response to the received transmitted pilot signals;

transmitting from the user equipment the weight adjustment to the base station;

receiving at the base station the transmitted weight adjustment from the user equipment;

processing a data signal 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;

weighting at least one of the processed data signal versions by a weight value adjusted in response to the received transmitted weight adjustment;

from each transmitting antenna, transmitting a different one of the data signal versions; and

receiving the transmitted data signal versions at the user equipment.

2. The method of claim 1 further comprising filtering the received data signal versions at the user equipment to recover data from the received data signal versions.

3. The method of claim 2 wherein the filtering is performed using an adaptive algorithm.

4. The method of claim 3 wherein the adaptive algorithm is a least mean square algorithm.

5. The method of claim 1 further comprising filtering the received transmitted pilot signals;

wherein the weight adjustment is derived from the filtered received transmitted pilot signals.

6. The method of claim 1 wherein the received data signal versions are distinguished by the at least the portion of each processed 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 pilot signals, each pilot signal having a different chip sequence than others of the plurality of pilot signals;

a weight calculation device configured to derive a weight adjustment in response to the received pilot signals; and

the receiving circuit configured to receive a plurality of data signal versions, at least a portion of each data signal has a different chip sequence than others of the plurality of data signal versions, the receiving circuit configured to filter the received data signal versions to recover data.

8. The user equipment of claim 7 wherein the weight adjustment device is configured to provide the weight adjustment for transmission.

9. The user equipment of claim 8 wherein the received plurality of data signal versions were processed in response to the weight adjustment.

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

11. The user equipment of claim 7 the receiving circuit is configured to filter 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 pilot signals;

wherein the weight adjustment device is configure to derive the weight adjustment from the filtered received transmitted 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.

15. A code division multiple access base station having a plurality of transmitting antennas, the base station comprising:

a data signal generator configured to produce a data signal;

a spreading device configured to spread the data signal and produce a plurality of data signal versions, each data signal version having at least a portion with a different chip sequence than the other data signal versions and each data signal version uniquely associated with one of the plurality of transmitting antennas;

a weighting device configured to weight at least one of the data signal versions by a weight value adjusted in response to a received weight adjustment; and

for each transmitting antenna, a combining device configured to combine the data signal version associated with than antenna with a pilot signal having a different chip sequence than the pilot signal of the other transmitting antenna, the combining device configured to provide the combined data signal version and pilot signal to that transmitting antenna for transmission.