Transmit diversity method and system
AssigneeNokia Corporation
InventorsAri Hottinen, Risto Wichman
Life of this patent
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Abstract
The invention relates to a transmit diversity method for a wireless communication system comprising a transmitting element and at least one receiver, wherein a transmission signal is transmitted from the transmitting element to the at least one receiver in accordance with a weight information determined in response to a feedback information. The feedback information is derived from the response at the at least one receiver to the transmission signal, and is fed back using multiplexed feedback signals. Multiple feedback signal quantization constellations and/or constellation specific feedback subchannels can be used for channel probing, such that the total feedback resolution and robustness can be enhanced, while maintaining low signaling capacity of the feedback channel.
Claims40
A transmit diversity method for a wireless communication system comprising a transmitting element and at least one receiver, said method comprising the steps of:
- a) transmitting from said transmitting element to said at least one receiver a transmission signal in accordance with a weight information determined in response to a feedback information;
- b) deriving at said at least one receiver said feedback information from the response to said transmission signal using at least two different quantization constellations;
- c) feeding back said feedback information using multiplexed feedback signals, wherein said multiplexed feedback signals comprise a first feedback signal having a first quantization constellation and a second feedback signal having a second quantization constellation.
A transmit diversity system for a wireless communication system, comprising:
- a) transmitting means (10) for transmitting a transmission signal from a transmitting element (A1, A2) in accordance to with a weight information determined in response to a feedback information;
- and
- b) at least one receiver (20) for receiving said transmission signal and deriving said feedback information from the response to said transmission signal using at least two different quantization constellations;
- c) wherein said at least one receiver (20) comprises feedback means (24, 25) for feeding back said feedback information using multiplexed feedback signals, wherein said feedback means (24, 25) is arranged to generate a first feedback signal having a first constellation and a second feedback signal having a second constellation.
A transmitter for a wireless communication system, comprising:
- a) extracting means (12) for extracting a feedback information from a received signal;
- b) transmitting means (11) for transmitting a transmission signal from a transmitting element (A1, A2) in accordance with a weight information;
- c) determining means (14) for determining said weight information in response to said extracted feedback information;
- and
- d) control means (13, 15) for controlling said determining means (14) so as to determine said weight information in accordance with multiplexed feedback signals used for feeding back said feedback information,
- wherein said control means (13, 15) comprises a switching means (13) for alternately switching a first feedback signal having a first constellation and a second feedback signal having a second constellation to said determining means (14).
A receiver for a wireless communication system, comprising:
- a) receiving means (21) for receiving a transmission signal;
- b) deriving means (22, 23, 24) for deriving a feedback information from the response to said transmission signal using at least two different quantization constellations;
- and
- c) feedback means (24, 25) for feeding back said feedback information using multiplexed feedback signals,
- wherein said deriving means (22, 23, 24) comprises extracting means (22) for extracting a probing signal transmitted with a known power, channel estimation means (23) for performing a channel estimation on the basis of said extracted probing signal, and generating means (24) for generating said multiplexed feedback signals on the basis of said channel estimation,
- and wherein said generating means (24) is arranged to generate a first feedback signal having a first constellation and a second feedback signal having a second constellation, wherein said feedback means (24, 25) is arranged to feed back said first and second feedback signals as said multiplexed feedback signals.
Dependencies are inferred from the claim text.