Patent ID: 6959047

Claim:
A space-time diversity transmitter that includes (a) n transmitting antennas, where n is greater than one, (b) an encoder of an applied information bit stream, said encoder developing n symbol streams, and (c) a constellation mapper responsive to said n symbol streams, for mapping symbols of each of said n symbol streams into a standard signal constellation to create a mapped stream, said constellation mapper applying each of the created n mapped stream to a different one of said n antennas, the improvement comprising: a generator of a symbols sequence; an encoder for creating n training sequences from said symbols sequence; and a training sequence mapper that maps said n training sequences onto a standard constellation to develop n mapped training sequences, and applies the n mapped training sequences to said n antennas at times when said constellation mapper stops applying said n mapped stream to said n antennas; where said n training sequences are selected to enable a receiver that receives said n training sequences to determine characteristics of a channel through which said n antennas communicate to said receiver, said n training sequences have a common length N t that is related to transmitted symbols memory, L−1, of communication medium interposed between said transmitter and said receiver, N t being at least equal to 2L−1, and said symbols sequence developed by said generator is N t +(n−2)L symbols long.