Conference paper
Maximum mutual information vector quantization of log-likelihood ratios for memory efficient HARQ implementations
Modern mobile telecommunication systems, such as 3GPP LTE, make use of Hybrid Automatic Repeat reQuest (HARQ) for efficient and reliable communication between base stations and mobile terminals. To this purpose, marginal posterior probabilities of the received bits are stored in the form of log-likelihood ratios (LLR) in order to combine information sent across different transmissions due to requests.
To mitigate the effects of ever-increasing data rates that call for larger HARQ memory, vector quantization (VQ) is investigated as a technique for temporary compression of LLRs on the terminal. A capacity analysis leads to using maximum mutual information (MMI) as optimality criterion and in turn Kullback-Leibler (KL) divergence as distortion measure.
Simulations run based on an LTE-like system have proven that VQ can be implemented in a computationally simple way at low rates of 2-3 bits per LLR value without compromising the system throughput.
Language: | English |
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Publisher: | IEEE |
Year: | 2010 |
Pages: | 30-39 |
Proceedings: | Data Compression Conference 2010 |
ISBN: | 1424464250 , 1424464269 , 9781424464258 and 9781424464265 |
ISSN: | 23750383 and 10680314 |
Types: | Conference paper |
DOI: | 10.1109/DCC.2010.98 |
ORCIDs: | Forchhammer, Søren and Andersen, Jakob Dahl |
AWGN Automatic repeat request Data compression Decoding Distortion measurement Error correction codes Kullback-Leibler divergence Mobile communication Mutual information Throughput Vector quantization automatic repeat request distortion distortion measure harq hybrid automatic repeat request log-likelihood ratios maximum mutual information memory efficient HARQ implementations mobile communication mobile telecommunication systems turbo codes vector quantisation vector quantization