Turbo Equalization for Receivers with Unreliable Buffer Memory

In this paper the effect of unreliable buffer memory on Turbo equalization is investigated. Under the assumption that the resulting bit errors are uniformly and independently distributed on receive and LLR buffer output, the effect of unreliable memory on the channel capacity is analyzed. It is further shown, that extrinsic information transfer and bit error rate (BER) performance of a conventional Turbo Equalizer are heavily degraded. Based on these observations a fault tolerant (FT) Turbo Equalizer is derived, which considers the memory error characteristics by using a modified transition metric for the involved MAP equalizer and decoder. It is demonstrated, that the FT Turbo Equalizer can effectively compensate memory errors and thus yields a significantly improved BER performance.