The joint Viterbi detector/decoder (JVDD) is a recently proposed receiver scheme that does both detection and decoding on a single trellis rather than doing detection on a trellis and decoding on factor graph as in th...
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ISBN:
(纸本)9781479969296
The joint Viterbi detector/decoder (JVDD) is a recently proposed receiver scheme that does both detection and decoding on a single trellis rather than doing detection on a trellis and decoding on factor graph as in the conventional iterative detector today. The JVDD attempts to return minimum metric legal codeword (MMLC) that is the optimum decision over an AWGN/ISI channel. However in so doing, the computational complexity quickly becomes untenable. In order to manage the computational complexity, GDLD and GDPD codes have been proposed that specifically target the complexity issue of the JVDD. In this work we perform a more in-depth study on several of the codes' parameters on both the performance and the complexity of the JVDD.
In an iterative receiver of a bandwidth-efficient multiuser space-time block coding (STBC) system, the extrinsic information is iteratively exchanged among the soft-input soft-output (SISO) channel decoders, the soft-...
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In an iterative receiver of a bandwidth-efficient multiuser space-time block coding (STBC) system, the extrinsic information is iteratively exchanged among the soft-input soft-output (SISO) channel decoders, the soft-output multiuser detector and the soft-output M-ary demodulators. Error performance, complexity and efficiency of the extrinsic information exchange are the most important properties of an iterative receiver. Taking these factors into account, sigma mapping is first applied to M-QAM constellations to yield a low-complexity soft-output minimum mean squared error (MMSE) demodulator to be used in the iterative receiver. Then a low-complexity two-loop iterative receiver is proposed for the multiuser STBC systems. It is shown that by running an additional inner iteration (between the channel decoders and the M-ary demodulators) for every outer iteration (between the channel decoders and the multiuser detector), the proposed receiver is superior to the conventional one, in which only one inner iteration is executed per one outer iteration. The results in this paper are therefore useful for wireless applications that employ space-time coding and require a very high bandwidth efficiency.
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