100 % channel reuse in orthogonal multiple-access systems

The uplink of a multicell synchronous multiple access system is investigated. Users within a cell are separated by use of orthogonal waveforms that generally remain orthogonal even in multipath conditions. These waveforms are reused in adjacent antenna beam sectors or adjacent cells to achieve a unity reuse factor. Interference protection is achieved even when beam cross-attenuation is small through error-correction coding and interleaving, modulation hopping, equalization of other user interference, and use of a single axis modulation such as binary phase-shift-keying. Reuse of channels in adjacent cells serviced by different base stations is supported by a macrodiversity technique in which signals from adjacent base stations are transferred over fixed communication links for interference processing at the desired user base station. Simulations at the same throughput rate for fixed and fading environments establish the superior performance of BPSK over conventional quadrature PSK with unity reuse