The numerically stable QRD-DMS receiver and overlapped channel transmission technique for slow frequency hopped multiple access networks

In this paper, we present an overlapped channel transmission (OCT) multiple access scheme which increases the uplink capacity of the slow FHMA systems. By using antenna array techniques, subscribers can transmit data through time-frequency overlapped slots and the proposed system increases the spectrum efficiency. A practical system that uses 2-fold OCT to increase system capacities with the same total bandwidth are proposed along with a fast processing and numerically stable beamforming algorithm and VLSI architecture. The beamforming weights can be calculated in one symbol´s duration and thus coherent combining can be achieved to further increase the beamforming performance