Space time transmit diversity with subgroup rate control and subgroup antenna selection in multi-input multi-output communications systems
First Claim
1. A method for transmitting an input stream of symbols in a multiple-input/multiple-output wireless communications system including M subgroups of transmitting antennas, comprising:
- selecting, according to channel conditions of the multiple-input/multiple-output wireless communications system, L subgroups of the M subgroups of antennas, where L<
M and each of the L subgroups of antennas includes a set of at least two antennas;
demultiplexing, the input stream into L substreams, there being one substream for each one of the L selected subgroups of at least two antennas;
adaptively modulating and coding each of the L sub streams to a maximum data rate while achieving a predetermined performance on an associated channel used to transmit the substream;
space-time transmit diversity encoding each of the L coded substreams into a set of at least two output streams, there being one output stream for each antenna in the set of at least two antennas of each one of the L subgroups of antennas, wherein the selecting is performed before the adaptively modulating and coding and the space-time transmit diversity encoding; and
transmitting the set of at least two output streams using the L subgroups of at least two antennas.
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Accused Products
Abstract
A method and system transmits an input stream of data symbols in a multiple-input/multiple-output wireless communications system that includes M subgroups of transmitting antennas. A stream of data symbols is provided to a combined switch and demultiplexer. The combined switch and demultiplexer selects a subset L of the M subgroups of antennas as active, where L<M. The demultiplexer then splits the data stream into L substreams, which are fed to the L subgroups of antennas. Before transmission, each of the L substreams is adaptively modulated and coded to a maximum data rate while achieving a predetermined performance on an associated channel used to transmit the substream. Space-time transmit diversity encoding is applied to each coded substream to generate multiple output streams, one output stream for each antenna of each of the L subgroups. The selection by the switch is based on channel conditions fed back by a receiver of the output streams.
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Citations
15 Claims
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1. A method for transmitting an input stream of symbols in a multiple-input/multiple-output wireless communications system including M subgroups of transmitting antennas, comprising:
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selecting, according to channel conditions of the multiple-input/multiple-output wireless communications system, L subgroups of the M subgroups of antennas, where L<
M and each of the L subgroups of antennas includes a set of at least two antennas;demultiplexing, the input stream into L substreams, there being one substream for each one of the L selected subgroups of at least two antennas; adaptively modulating and coding each of the L sub streams to a maximum data rate while achieving a predetermined performance on an associated channel used to transmit the substream; space-time transmit diversity encoding each of the L coded substreams into a set of at least two output streams, there being one output stream for each antenna in the set of at least two antennas of each one of the L subgroups of antennas, wherein the selecting is performed before the adaptively modulating and coding and the space-time transmit diversity encoding; and transmitting the set of at least two output streams using the L subgroups of at least two antennas. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A system for transmitting an input stream of symbols in a multiple-input/multiple-output wireless communications system including M subgroups of transmitting antennas, comprising:
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a switch configured to select, according to channel conditions of the multiple-input/multiple-output wireless communications system, L subgroups of the M subgroups of antennas, where L<
M and each of the L subgroups of antennas includes a set of at least two antennas;a demultiplexer configured to split the input stream into L substreams, there being one substream for each one of the L subgroups of at least two antennas; means for adaptively modulating and coding each of the L substreams to a maximum data rate while achieving a predetermine performance on an associated channel used to transmit the substream, wherein the switch selects before adaptively modulating and coding and space-time transmit diversity encoding; and means for space-time transmit diversity encoding each of the L coded substream into a set of at least output streams, there being one output stream for each antenna in the set of at least two antennas of each one of the L subgroups of antennas.
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Specification