A COMPARISON OF SCALAR QUANTIZATION STRATEGIES FOR NOISY CHANNEL DATA-TRANSMISSION

It is known that the combination of uniform quantization and entropy c oding performs optimally at asymptotically high rates. However, due to synchronization problems resulting from the use of variable length co des, this is true only in the absence of transmission errors. Thus, th e performance over noisy channels can be improved by using either fixe d length codes and Lloyd-Max quantization or by adding end-of-line sym bols. In this paper, computer simulations are used to compare the abov e two schemes for a variety of error rates, line lengths and amounts o f error protection. It is found that the ''uniform'' scheme gives the best SNR for a given rate in the case of memoryless Gaussian and Lapla cian sources, provided that its parameters are chosen sensibly. It is expected that these results will generalize to other sources.