Efficient channel coding and interleaving schemes for mobile radio communications

Motivated by the increasing demand for high quality, robust yet bandwidth efficient data and speech communications in the hostile mobile radio environment the authors embarked on the comparative study of a number of multilayer forward error correction (FEC) and interleaving scenarios. The basic attributes of speech and data communication channels are entirely different. Speech transmission channels must not have long coding delays, but their bit error rates (BER) are allowed to be higher than those for data transmission. However, the higher data integrity required for data transmission can be achieved by deploying longer coding/interleaving delays, which are tolerated in this application. To limit the plurality of scenarios and system parameters to a manageable number we suppose an overall coding rate of one half. They postulate the memorylength of speech channels to be around 450 bits, while that of data channels to be around five times as long, i.e. 2500 bits