Code assignment for hidden terminal interference avoidance in multihop packet radio networks

Hidden terminal interference is caused by the simultaneous transmission of two stations that cannot hear each other, but are both received by the same destination station. The authors investigate the problem of assigning orthogonal codes to stations to eliminate the hidden terminal interference and minimize the number of codes used. It is shown that this problem is computationally intractable, even for very restricted but very realistic network topologies. Optimal algorithms for code assignment in special networks, as well as both centralized and distributed suboptimal heuristic algorithms for general topologies, are presented. The results of extensive simulations to derive the average performance of the proposed heuristics on realistic network topologies are presented