A research study submitted in partial fulfillment of requirement for the degree of Master of Engineering, School of Advanced Technologies

Special Studies Project Report (M.Eng.) - Asian Institute of Technology, 2002

Recently, Trellis Coded Quantization (TCQ) has been continuously developed and applied in data compression due to its low complexity and good performance. Trellis Coded Modulation (TCM) has also proven its important role in both bandwidth constraint and power constraint channels such as wireless channels. In this research study, the perfo1mance of joint TCQ/TCM with different bit allocations and complexities between source and channel coding is investigated. The complexities are the truncation delay lengths which are used in TCQ encoding and TCM decoding. The performance of joint TCQ/TCM over frequency selective fading channels is also evaluated and compared with performance of combination of TCQ and uncoded QPSK. The simulation results show that for A WGN channels, at low (less than 1 dB) and high values (greater than 4 dB) of channel SNR we should reserve more complexity and system resource (number of bits) for source coding. However, at medium range of channel SNR, those should be reserved for channel coding. For frequency selective fading channel (both independent fading and correlated fading), the joint TCQ/TCM always outperforms the combination of TCQ and uncoded QPSK for medium to high channel SNR. At low channel SNR, the performance of combination of TCQ and uncoded QPSK is better. The crossovers at which we should switch from combination of TCQ and uncoded QPSK to joint TCQ/TCM are 2 dB and 5 dB for independent and correlated fading channels respectively.