Complex vector quantization codebook for use in downlink multi-user MIMO mobile broadcast systems
AssigneeAlcatel Lucent
InventorAlexei Ashikhmin
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Abstract
A wireless communications device having a complex vector quantization codebook for use in a downlink multi-user MIMO (multiple-input-multiple-output) mobile broadcast system with feedback enables the interference between data simultaneously sent by the base station to a plurality of mobile terminals to be reliably minimized. The codebook contains many subsets of code vectors that are substantially mutually (i.e., pairwise) orthogonal, or almost orthogonal, to each other. With use of such a codebook, a base station can transmit simultaneously to subsets of mobile terminals associated with these subsets of code vectors with minimal interference therebetween.
Claims20
A wireless communication device comprising a complex vector quantization codebook for use in a downlink multi-user MIMO mobile broadcast system with feedback, the codebook comprising r entries, each entry comprising M elements, the codebook comprising at least X distinct subsets of M of said r codebook entries that are substantially mutually orthogonal, wherein X is at least twenty percent more than a statistically expected number of distinct subsets of M codebook entries that would be substantially mutually orthogonal to each other in a randomly generated codebook of r entries, each such entry comprising M elements.
A wireless communication device comprising a complex vector quantization codebook for use in a downlink multi-user MIMO mobile broadcast system with feedback, wherein the codebook has been generated based on both binary Reed-Muller codes and en Reed-Muller codes over Z4.
A wireless communication device comprising a complex vector quantization codebook for use in a downlink multi-user MIMO mobile broadcast system with feedback, wherein the codebook has been generated based on binary Reed-Muller codes and on Reed-Muller codes over Z4,
- wherein said codebook as generated based on binary Reed-Muller codes and on Reed-Muller codes over Z4 has been modified by the addition of one or more random code vectors thereto, such that the number of entries comprised in said codebook is a power of two.
A wireless communication device comprising a complex vector quantization codebook for use in a downlink multi-user MIMO mobile broadcast system with feedback, wherein the codebook has been generated based on binary Reed-Muller codes and on Reed-Muller codes over Z4,
- wherein said codebook as generated based on binary Reed-Muller codes and on Reed-Muller codes over Z4 has been modified by the removal of one or more code vectors therefrom, such that the number of entries comprised in said codebook is a power of two.
A method of operating a wireless communication device comprising a complex vector quantization codebook for use in a downlink multi-user MIMO mobile broadcast system with feedback, the method comprising the steps of:
- receiving a plurality of codebook indices from a corresponding plurality of terminals, the plurality of codebook indices representing a corresponding plurality of codebook entries, each codebook entry comprising M elements, and matching (i) one or more subsets of M of said plurality of codebook entries represented by said conesponding plurality of said codebook indices to (ii) one or more predetermined subsets of M codebook entries of the codebook, wherein the codebook entries comprised in each of said predetermined subsets of M codebook entries are substantially mutually orthogonal.
Dependencies are inferred from the claim text.