A method and system that increases transmit diversity gain in a wireless communication
system. The system includes a transmitter with 2N transmit antennas,
where N is greater than one, and a receiver with one or more receive antenna. The
transmitter includes N stages connected serially to each other. The first stage
is a symbol level space-time transmit diversity encoder. Each of the next N-1 stages
is a block level space-time transmit diversity encoder, for a total of N stages.
The last stage is connected to the 2N antennas. The transmitter generates
pairs of symbols in a form X1 and X2, The pairs of symbols
are encoded by the first stage to produce a 2121 output
matrix C. Then, in each next block level stage n, the 2n-12n-1
output matrix of a previous stage is encoded to a 2n2n
output matrix, until a final output matrix has 2N rows of transmit
symbols. The transmit symbols of the final output matrix are fed, in a left-to-right
order, for each row, in a top-to-bottom order, to a corresponding different one
of the 2N transmit antennas. A transmit weight is applied to each transmit
symbol before transmitting the transmit symbol.