Abstract: A system and method using multiple request to send (RTS) messages to enhance wireless communication resource allocation. The system and method operates a receiver to receive an RTS message from a station operating in, for example, a very high throughput wireless local area network, and in response, to transmit an ask for request (AFR) message. The receiver can receive multiple RTS messages and in response, issue respective AFR messages, to thus perform RTS negotiation of resources for access by the stations. If the receiver fails to receive any further RTS messages due to, for example, collision of RTS messages sent by multiple stations or failure of any other stations to send an RTS message, the receiver can then issue a clear to send (CTS) message indicating to all stations that have sent an RTS message that they are clear to send to the receiver using the information contained in the AFR message.

Abstract: A transmitter generates a constellation pattern comprising replications of a first constellation. Each replication has a replication offset relative to a neighbouring replication and alternates between corresponding to the first constellation and an axis mirrored constellation (mirrored around the real and/or imaginary axis). The transmitter selects from the pattern such that a symbol for a data value corresponding to a first constellation point of the first constellation is selected from all replications of this constellation point. The constellation point resulting in the lowest transmit power for a combination of a plurality of antennas may be selected. A receiver receives the selected symbol and provides a folding operation to compensate for replications and mirroring. The replication offset may be lower than the minimum distance between symbols in the first constellation thereby resulting in an improved trade off between transmit power and error probability, e.g.

Abstract: A communication system comprises a set of user equipments which are arranged to simultaneously transmit a signal over an air interface to a base station. Each of the transmitted signals comprises a data stream encoded by a space time block code and transmitted on multiple antennas. Specifically, an Alamouti code may be used. The base station generates a received data stream for each of the set of user equipments by joint space time block code decoding of the signals from the set of user equipments. The invention may provide improved performance and increased capacity and may in particular provide efficient multi user operation for a system using space time block codes. The user equipments may be scheduled in response to cross interference metrics reflecting a cross interference between simultaneously transmitting user equipments.

Abstract: A Multiple In Multiple Out (MIMO) communication system comprises an air interface scheduler for allocating air interface resource to a plurality of user equipments transmitting to a MIMO receiver. A vector processor of the scheduler determines a receive equalizer vector for the MIMO receiver for each of a plurality of user equipments in response to a channel matrix for the user equipment. The vector processor may specifically apply singular value decomposition to the channel matrix to determine the receive equalizer vector. An orthogonality processor then determines orthogonality measures between receive equalizer vectors for different sets of user equipments. A selection processor selects a set of user equipments to be allocated a shared MIMO air interface resource in response to the orthogonality measures. By scheduling in response to orthogonality of receiver operations, a reduced interference and/or reduced receiver complexity can be achieved.

Abstract: Disclosed is a method and apparatus for encoding a modulated signal in a communication system. The method comprises generating an initial constellation, applying a vertical axis symmetry to the initial constellation to generate a first resulting constellation, translating the first resulting constellation to a left direction of the initial constellation to produce a left flipped constellation, applying a horizontal axis symmetry to the initial constellation to generate a second resulting constellation, translating the second resulting constellation to an up direction of the initial constellation to produce an up flipped constellation, applying a central axis symmetry to the initial constellation to generate a third resulting constellation; and translating the third resulting constellation to a left-up direction of the initial constellation to produce a left-up flipped constellation.

Abstract: A Multiple In Multiple Out (MIMO) communication system comprises an air interface scheduler for allocating air interface resource to a plurality of user equipments transmitting to a MIMO receiver. A vector processor of the scheduler determines a receive equalizer vector for the MIMO receiver for each of a plurality of user equipments in response to a channel matrix for the user equipment. The vector processor may specifically apply singular value decomposition to the channel matrix to determine the receive equalizer vector. An orthogonality processor then determines orthogonality measures between receive equalizer vectors for different sets of user equipments. A selection processor selects a set of user equipments to be allocated a shared MIMO air interface resource in response to the orthogonality measures. By scheduling in response to orthogonality of receiver operations, a reduced interference and/or reduced receiver complexity can be achieved.

Abstract: A transmitter generates a constellation pattern comprising replications of a first constellation. Each replication has a replication offset relative to a neighbouring replication and alternates between corresponding to the first constellation and an axis mirrored constellation (mirrored around the real and/or imaginary axis). The transmitter selects from the pattern such that a symbol for a data value corresponding to a first constellation point of the first constellation is selected from all replications of this constellation point. The constellation point resulting in the lowest transmit power for a combination of a plurality of antennas may be selected. A receiver receives the selected symbol and provides a folding operation to compensate for replications and mirroring. The replication offset may be lower than the minimum distance between symbols in the first constellation thereby resulting in an improved trade off between transmit power and error probability, e.g.

Abstract: A transmitter and receiver communicate using a modified superposition coding scheme. The transmitter transits superposition symbols which include a near end symbol for a near receiver and a far end symbol for a far receiver. The transmitter modifies the near end symbol depending on the far end symbol prior to transmission. Specifically, the near end symbol may be mirrored around the real or imaginary axis. The near receiver generates mirrored superposition symbols by applying mirroring to each received superposition symbol around at least one of the real axis and the imaginary axis in response to the value of the received symbol. The mirroring may remove the uncertainty of the far end symbol value allowing a simpler decision for the near end symbol. The mirroring performed by the transmitter and the near receiver will negate each other for the near end symbol thereby allowing a simplified near end receiver operation.

Abstract: A system and method using multiple request to send (RTS) messages to enhance wireless communication resource allocation. The system and method operates a receiver to receive an RTS message from a station operating in, for example, a very high throughput wireless local area network, and in response, to transmit an ask for request (AFR) message. The receiver can receive multiple RTS messages and in response, issue respective AFR messages, to thus perform RTS negotiation of resources for access by the stations. If the receiver fails to receive any further RTS messages due to, for example, collision of RTS messages sent by multiple stations or failure of any other stations to send an RTS message, the receiver can then issue a clear to send (CTS) message indicating to all stations that have sent an RTS message that they are clear to send to the receiver using the information contained in the AFR message.

Abstract: A communication system comprises a set of user equipments which are arranged to simultaneously transmit a signal over an air interface to a base station. Each of the transmitted signals comprises a data stream encoded by a space time block code and transmitted on multiple antennas. Specifically, an Alamouti code may be used. The base station generates a received data stream for each of the set of user equipments by joint space time block code decoding of the signals from the set of user equipments. The invention may provide improved performance and increased capacity and may in particular provide efficient multi user operation for a system using space time block codes. The user equipments may be scheduled in response to cross interference metrics reflecting a cross interference between simultaneously transmitting user equipments.

Abstract: Disclosed is a method and apparatus for encoding a modulated signal in a communication system. The method comprises generating an initial constellation, applying a vertical axis symmetry to the initial constellation to generate a first resulting constellation, translating the first resulting constellation to a left direction of the initial constellation to produce a left flipped constellation, applying a horizontal axis symmetry to the initial constellation to generate a second resulting constellation, translating the second resulting constellation to an up direction of the initial constellation to produce an up flipped constellation, applying a central axis symmetry to the initial constellation to generate a third resulting constellation; and translating the third resulting constellation to a left-up direction of the initial constellation to produce a left-up flipped constellation.