The Design and Implementation of Unequal Error-Correcting Coding Systems

The theoretical basis for using the mean-square error criterion in channel coding systems has been established previously. Such a criterion leads to an unequal error-correcting system. This paper describes the design methods for translating that theory into practice. It also presents some new results concerning the performance of these types of systems. The relationship of the mean-square system to the one based on the minimum probability of error is examined. Except for very noisy channels the two decoders produce indentical outputs for all correctable error patterns. However, the mean-square error decoder guarantees various levels of correcting capabilities for the more significant positions during overload conditions.