METHOD AND SYSTEM FOR DATA COMMUNICATION

• US 20090279442A1
• Filed: 05/06/2009
• Published: 11/12/2009
• Est. Priority Date: 05/09/2008
• Status: Active Grant

• Current Assignee: Vodafone Holding GmbH (Vodafone Group PLC)
• Original Assignee: Vodafone Holding GmbH (Vodafone Group PLC)
• Inventors: Rave, Wolfgang
• Granted Patent: US 8,412,260 B2
• Time in Patent Office: Days
• US Class Current: 370/246
• CPC Class Codes: H04L 1/0048 in conjunction with detection of multiuser or interfering signals, e.g. iteration between CDMA or MIMO detector and FEC decoder for spatial equalizer H04L25/03286
• CPC Class Codes: H04L 25/067 providing soft decisions, i.e. decisions together with an estimate of reliability H04L25/068 and H04L25/069 take precedence; sequence estimation techniques H04L25/03178

Abstract

There is provided a system and method for multi-user detection by a plurality of base stations situated at different geographical locations through base station cooperation. An exemplary method comprises exchanging detected data iteratively while performing separate detection and decoding of received data streams.

Claims

1-17. -17. (canceled)

18. A method for multi-user detection by a plurality of base stations situated at different geographical locations through base station cooperation, the method comprising exchanging detected data iteratively while performing separate detection and decoding of received data streams.

19. The method recited in claim 18, comprising exchanging processed information relating to associated mobile terminals between the base stations.

20. The method recited in claim 18, comprising exchanging only processed information relating to associated mobile terminals between the base stations.

21. The method recited in claim 18, comprising calculating local estimates of dominant interferers of at least two base stations.

22. The method recited in claim 21, comprising combining local estimates of dominant interferers of a first subset of the plurality of base stations with independently received copies from a second subset of the plurality of base stations.

23. The method recited in claim 21, comprising combining the local estimates for the at least two base stations with their independently received copies from other ones of the plurality of base stations.

24. The method recited in claim 22, wherein the first subset of the plurality of base stations comprises most of the plurality of base stations.

25. The method recited in claim 18, comprising:

calculating local estimates of dominant interferers of the plurality of base stations; and

combining the local estimates with independently received copies from at least some of the plurality of base stations.

26. The method recited in claim 18, comprising generating local estimates of dominant interferers at each of the plurality of base stations using single-antenna interference cancellation techniques.

27. The method recited in claim 18, comprising exchanging soft-bits among the plurality of base stations.

28. The method recited in claim 27, comprising exchanging quantized Lvalues for which optimum quantization and decision levels have been obtained based on a density of associated soft-bit values and not on a density of the L-values.

29. The method recited in claim 18, comprising increasing an average amount of mutual information communicated with a proposed quantization scheme with respect to direct quantization of an L-value density.

30. The method recited in claim 18, wherein used levels vary with mean and variance of a currently to be transmitted block of L-values.

31. The method recited in claim 18, comprising estimating a data rate required for the exchange of quantized L-values by exploiting the fact that used quantization levels differ strongly in their respective probabilities, wherein the levels can represented with an entropy coding technique and prefix-free codes using labels of different length.

32. A communication system that is adapted to carry out communication between a plurality of communication devices situated at different geographical locations, each of the communication devices being adapted to exchange detected data iteratively while performing separate detection and decoding of received data streams.

33. The communication system recited in claim 32, wherein each of the communication devices comprises a logical node.

34. A mobile communication device that is adapted to communicate with a plurality of base stations, the plurality of base stations being situated at different geographical locations, each of the plurality of base stations being adapted to exchange detected data iteratively while performing separate detection and decoding of received data streams.