Patent ID: 7154964

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 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 streams to a different one of said n transmitting antennas, the improvement comprising: a generator of a symbols sequence, s; an encoder for creating n training sequences from said symbols sequence, where each of the created n training sequences has an impulse-like autocorrelation function and zero cross correlation relative to the other of the n created training sequences; 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 wherein said n training sequences are of length N t ≧2L−1, and N t =kN PRUS +L−1, where L is an integer corresponding to a number of channel parameter unknowns that need to be estimated through which channel said transmitter communicates with a receiver, k is an integer greater than or equal to 1, and N PRUS is a length of a perfect roots-of-unity sequence of length N.