An adaptive beamspace algorithm for mobile satellite communications systems using orthogonal waveforms and convolutional codes

It is shown that convolutional codes combined with orthogonal waveforms over the complex field provide both co-channel interference mitigation and reduced order computations for a multi-beam antenna. Reduced computational complexity is achieved by selecting a subset of the fixed beams based on a threshold computed from estimates of the bit error rates (BER) at the outputs of each of the beams. The subset of beams is subsequently used to perform adaptive beamspace processing to reduce the co-channel interference. Finally, the performance of the algorithm is evaluated via computer simulations for both fading and non-fading channels in the presence of co-channel interference