A low-complexity tree-search algorithm to decode diversity-oriented block codes with inter-symbol interference

In order to contain a differential propagation delay in a block based cooperative Multiple-Input-Multiple-Output (MIMO) system, a guard interval can be inserted to mitigate the effect of inter-symbol interference. A larger block size could substantially increase the effective symbol rate, although at the expense of decoding complexity. In this paper, we propose a novel low-complexity breadth-adjustable tree-search algorithm, which, as an example, has been applied to decode Asynchronous Cooperative Liner Dispersion Codes (ACLDC). With simulation we demonstrate that when the blocksize is equivalent to 20, the complexity of the proposed algorithm is only a fraction of 10^-8 of that of the Maximum Likelihood (ML) algorithm. This would allow us to practically enhance the effective symbol rate without any performance degradation.