Title :
A Low-cost 60 GHz OFDM modem
Author_Institution :
NICTA, Eveleigh, NSW, Australia
Abstract :
A simple soft-demapping scheme for rectangular quadrature amplitude modulation (R-QAM) signals is developed for a low-cost 60 GHz OFDM baseband chip design, conforming to the IEEE802.15.3C standard. The scheme is equally applicable to a generic bit-interleaved orthogonal frequency division multiplexing (OFDM) modulation for both square QAM (S-QAM) and R-QAM constellations. The channel coding employs the concatenation of convolutional and Reed-Solomon (RS) codes. Simulation shows that this simple soft-demapping scheme effectively achieves the same performance of an optimum log-likelihood ratio (LLR) demapper. The exact formula for the difference between the proposed approximate LLR and the optimum LLR is derived.
Keywords :
OFDM modulation; Reed-Solomon codes; convolutional codes; costing; modems; OFDM modem; R-QAM constellation; Reed-Solomon codes; convolutional codes; frequency 60 GHz; optimum log-likelihood ratio demapper; soft-demapping scheme; square QAM constellation; Baseband; Channel coding; Chip scale packaging; Convolution; Convolutional codes; Modems; OFDM modulation; Quadrature amplitude modulation; Reed-Solomon codes; Standards development; 60 GHz; Gigabit wireless modem; LLR; OFDM; QAM; Reed-Solomon code; Soft-decision decoding; Viterbi algorithm;
Conference_Titel :
Information, Communications and Signal Processing, 2009. ICICS 2009. 7th International Conference on
Conference_Location :
Macau
Print_ISBN :
978-1-4244-4656-8
Electronic_ISBN :
978-1-4244-4657-5
DOI :
10.1109/ICICS.2009.5397610
