Spreading matrices from PN sequences

We propose a simple method for the generation of signature matrices for a space-time spreading (STS) system with BPSK modulation, where a signature sequence assigned to a user is paritioned into segements and the segments are assigned to the transmit antennas of the user. We show that, if the signature sequences are linearly independent, the STS system does not has an error floor in its BER performance and, of course, achieve the full receive antenna diversity. For the signature matrices generated from the M-sequences or Gold sequences, the BER performance of the system with likelihood ascent search detectors is superior to the V-BLAST system with the maximum-likelihood (ML) detectors. Moreover, for a large processing gain, the BER performance of the proposed system approaches the least upper bound derived previously.