Two signaling schemes for improving the error performance of frequency-division-duplex (FDD) transmission systems using transmitter antenna diversity

TLDR: Two signaling schemes that exploit the availability of multiple (N) antennas at the transmitter to provide diversity benefit to the receiver are proposed.

Abstract: Two signaling schemes that exploit the availability of multiple (N) antennas at the transmitter to provide diversity benefit to the receiver are proposed. In the first scheme, a channel code of length N and minimum Hamming distance d/sub min/ /spl les/ N is used to encode a group of K information bits. The channel code symbol c/sub i/ is transmitted with the i/sup th/ antenna. At the receiver, a maximum likelihood decoder for the channel code provides a diversity of d/sub min/, as long as each transmitted code symbol is subjected to independent fading. The second scheme introduces deliberate resolvable multipath distortion by transmitting the data bearing signal with antenna 1, and N - 1 delayed versions of it with antennas 2 through N. The delays are unique to each antenna and are chosen to be multiples of the symbol interval. At the receiver, a maximum likelihood sequence estimator resolves the multipath in an optimal manner to realize a diversity benefit of N.