POWER AND CONFIDENCE ORDERED LOW COMPLEXITY SOFT TURBO-MUD WITH VOTING SYSTEM

摘要

A real-time multi-user detection (MUD) receiver processing simultaneous digitally modulated interferers and transmissions in the same frequency optimizing performance for heavily loaded and overloaded multiple access systems implementing an iterative TurboMUD receiver using tree-pruning, including confidence ordering, power-ordering, and a voting procedure (330). On the first iteration, user indices are ordered according to received powers. On subsequent iterations, the voting system provides soft decisions or confidence values utilized as soft inputs to single-user decoders (340). Voting (330) is computationally attractive and allows the bank of decoders to operate on soft values, improving performance and reducing the number of turboMUD iterations. The bank of soft output error correction decoders produces an improved set of soft decisions or confidence values corresponding to the channel bits transmitted by each interfering user. Confidence values from the bank of decoders are used to order user indices, allowing the tree pruned MUD detector (320) to operate on the most reliable symbols first, improving the likelihood that pruning is correct. Subsequent confidence ordering and estimate refinement occurs until conditions are satisfied and iterative processing completed.