Multi-cast communication system and method of estimating channel impulse responses therein

A method of determining channel impulse responses of a plurality of channels established between a plurality of transmitting elements and a communication device in a communication system, the method comprising:

• substantially simultaneously transmitting different training bursts from each of the plurality of transmitting elements, each burst having a length at least as long as a maximum channel duration in the communication system multiplied by a number corresponding to the plurality of transmitting elements;
• recovering at the communication device a signal sequence yn from the different training bursts sn;
• and
• resolving the plurality of channels to recover associated channel impulse responses H for each channel by solving an algebraic matrix operation expressed in matrix-vector form as Y=SH, where:
• S is a matrix of partial training bursts for each channel, each training burst segmented into N pieces in the time domain;
• Y is a vector of a received signal sequence;
• and H is a concatenation of different channel impulse response vectors.

A computer program product for a processor within a receiver device, the computer program product comprising:

• code that performs transform operations on both a replica of a signal sequence sn and a received training sequence yn received by the communication device in at least one burst, the received training sequence yn being the signal sequence as received through a channel, the transform operations arranged to generate a multiplicity of signal sequence frequency bins and a multiplicity of training sequence frequency bins;
• code that performs point-by-point operations between corresponding signal sequence frequency bins and training sequence frequency bins;
• and
• code that concatenates the point-by-point operations associated with the channel to provide a composite frequency response for the channel, the composite frequency response allowing, in the time domain, generation of the channel impulse response for the channel;
• wherein the codes reside in a computer readable medium.

A communication device having a receiver coupled, in use, to receive a plurality of channels supporting a signal sequence yn and training sequence bursts, the communication device having:

• a signal processing platform to perform transform operations on both a replica of a signal sequence sn and a received training sequence yn received by the communication device in at least one burst, the received training sequence yn being the signal sequence as received through a channel, the transform operations arranged to generate a multiplicity of signal sequence frequency bins and a multiplicity of training sequence frequency bins;
• the signal processing platform arranged to perform point-by-point operations between corresponding signal sequence frequency bins and training sequence frequency bins;
• and
• the signal processing platform further arranged to concatenate the point-by-point operations associated with the channel to provide a composite frequency response for the channel, the composite frequency response allowing, in the time domain, generation of the channel impulse response for the channel.

A communication device operational to receive a plurality of training sequences on a plurality of channels and a signal sequence yn, the communication device comprising:

• a receiver for substantially simultaneously receiving, in use, different training bursts from each of the plurality of channels emanating from a plurality of transmit elements, each burst having a length at least as long as a maximum channel duration multiplied by a number corresponding to the plurality of transmit elements;
• recovery circuitry for recovering, in use, the signal sequence yn from the different training bursts sn;
• and
• a processor arranged to resolve the plurality of channels to recover associated channel impulse responses H for each channel by solving an algebraic matrix operation expressed in matrix-vector form as Y=SH, where:
• S is a matrix of partial training bursts for each channel, each training burst segmented into N pieces in the time domain;
• Y is a vector of a received signal sequence;
• and H is a concatenation of different channel impulse response vectors.

A base station of a communication system, the base station comprising:

• a transmitter chain arranged to transmit multiple quasi-orthogonal pseudo-noise sequences as training bursts sn from at least one transmit element and further arranged to transmit a signal sequence yn, successive training bursts providing an extended training sequence for use in channel estimation at a communication device of the communication system, the transmitter chain substantially simultaneously transmitting, in use, different training bursts from each of the at least one transmit element, each training burst having a length at least as long as a maximum channel duration in the communication system multiplied by a number corresponding to a plurality of channels to the communication device, the extended training sequence and the signal sequence yn providing a resolution mechanism to the communication device allowing the communication device to resolving the plurality of channels to recover associated channel impulse responses H for each channel by solving an algebraic matrix operation expressed in matrix-vector form as Y=SH, where:
• S is a matrix of partial training bursts for each channel, each training burst segmented into N pieces in the time domain;
• Y is a vector of a received signal sequence;
• and H is a concatenation of different channel impulse response vectors.