Antenna Selection Apparatus and Methods

• US 20080285686A1
• Filed: 07/31/2006
• Published: 11/20/2008
• Est. Priority Date: 07/29/2005
• Status: Abandoned Application

• Current Assignee: The Governors of the University of Alberta (University of Alberta)
• Original Assignee: The Governors of the University of Alberta (University of Alberta)
• Inventors: Beaulieu, Norman, Li, Wenyu
• Application Number:
  US11/997,103
• Publication Number:
  US 20080285686A1
• Time in Patent Office: Days
• US Class Current: 375/329
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 1/241 used in mobile communications, e.g. GSM H01Q1/247, H01Q1/248 take precedence
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• 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 7/0874 using subgroups of receive antennas
• CPC Class Codes: H04B 7/0891 Space-time diversity rake receivers H04B1/7115; space-time decoding H04L1/0631

Abstract

An apparatus and method for antenna selection diversity are provided. Antennas are selected by summing moments of space-time block encoded signals received via each respective antenna and selecting at least one antenna with the largest moment sum.

Claims

1. Apparatus for selecting N communication signals from a plurality M of communication signals received via respective antennas containing a length L STBC (space-time block code), where M≧

2, M≧

N≧

1, L≧

2, the apparatus comprising a selector configured to;

for each receive antenna, determine a respective moment of a raw signal plus noise sample of the communication signal received on the receive antenna for each of L time intervals of a block code duration of the STBC and sum these moments to produce a respective moment sum; and

select the N communication signals that have the N largest moment sums for subsequent communication signal processing.

2. The apparatus of claim 1, wherein the selector comprises a plurality of moment calculators for respective connection to a plurality of communication signal receiver branches comprising the respective antennas, and configured to calculate the sums of moments of the communication signals received through the plurality of communication signal branches.

3. The apparatus of claim 1, wherein the communication signals received through an i^th communication signal receiver branch comprise diversity signals r_j,i received from transmitter antennas during j=1, . . . , L time intervals of an STBC block code duration, and wherein for each of the communication signal receiver branches, the moment sum is determined by summing |r_j,i| or |r_j,i|ⁿ for all the L time intervals, where n>

=2.

4. The apparatus of claim 2, wherein the communication signals received through an i^th communication signal receiver branch comprise diversity signals r_j,i received from transmitter antennas during j=1, . . . , L time intervals of an STBC block code duration, and wherein for each of the communication signal receiver branches, the moment sum is determined by summing |r_j,i| or |r_j,i|ⁿ for all the L time intervals, where n>

=2.

5. The apparatus of claim 1, wherein the STBC comprises an Alamouti code.

6. The apparatus of claim 1, wherein the communication signals comprise symbols generated using any one of:

a coherent modulation scheme, a non coherent modulation scheme and a differential modulation scheme.

7. The apparatus of claim 1, wherein the communication signals comprise symbols generated using any one of:

Binary Phase Shift Keying (BPSK) and MPSK.

8. The apparatus of claim 1, wherein the selector is further configured to determine whether a difference in amplitudes of respective communication signals received through the selected communication signal receiver branch and another communication signal receiver branch of the plurality of communication signal receiver branches exceeds a threshold, and to select the another communication signal receiver branch where the difference exceeds the threshold.

9. The apparatus of claim 1, wherein the subsequent communication signal processing comprises at least one of:

space-time signal combining and signal detection.

10. The apparatus of claim 1 wherein M=2 and N=1.

11. The apparatus of claim 1 wherein N=2.

12. A communication device comprising:

a plurality of antennas for receiving space-time block code STBC encoded diversity communication signals from a plurality of transmitter antennas;

an apparatus according to claim 1 operatively coupled to the plurality of antennas; and

a communication signal processing path operatively coupled to the apparatus and configured to process the selected communication signals.

13. The communication device of claim 12, wherein the communication device comprises any one of:

a communication network base station and a mobile terminal.

14. A communication system comprising:

a communication network comprising a network element; and

a wireless communication device configured for communicating with the network element,

at least one of the network element and the wireless communication device comprising the apparatus of claim 1.

15. A communication system comprising:

a communication network comprising a network element; and

a wireless communication device configured for communicating with the network element,

at least one of the network element and the wireless communication device comprising the communication device of claim 12.

16. The communication system of claim 14, wherein at least one of the network element and the wireless communication device comprises a plurality of transmitter antennas for transmitting the communication signals containing the length L space-time block code.

17. The communication system of claim 15, wherein at least one of the network element and the wireless communication device comprises the plurality of transmitter antennas.

18. A communication signal receiver branch selection method comprising:

for each of a plurality of receiver branches, determining a respective moment sum of signal plus noise samples of space-time diversity communication signals over a space-time block code length, each communication signal receiver branch being operatively coupled to a respective antenna for receiving communication signals from a plurality of transmitter antennas;

selecting at least one communication signal receiver branch from the plurality of communication signal receiver branches having the largest moment sum; and

providing communication signals from the selected communication signal receiver branch for subsequent communication signal processing.

19. The method of claim 18, further comprising, after selecting:

determining moment sums of communication signals received through the selected communication signal receiver branch and others of the plurality of communication signal receiver branches;

determining whether a difference in moment sums of communication signals received through the selected communication signal receiver branch and another communication signal receiver branch of the plurality of communication signal receiver branches exceeds a threshold; and

selecting the another communication signal receiver branch where the difference exceeds the threshold.

20. A machine-readable medium storing instructions which when executed perform the method of claim 19.