Asynchronous Differential Space-Time Block Codes Based On Spreading Techniques Over Satellite Communication

In satellite cooperative communication system, delay errors caused by different delay between different channels with large scale relays brings loss of BER. Traditional solutions generally use differential codes to estimate channel parameters dynamically in the receiving end of a satellite communication system. In this paper, orthogonal codes in spread spectrum technique systems are used to distinguish signals from different relay satellites. In this paper, spread spectrum codes table is used to extract signals from different relay satellites, then to carry out a space-time decoding. As can be seen in simulation results, differential space-time blocks codes with spreading has a better BER than the one without spreading. It solves the problem of random delay, so that the receiving end of the channel should not to estimate channel parameter. The complexity of the receiving end is significantly reduced.