A type-aware coding approach for unequal message protection

Abstract

In this paper, to achieve an unequal message protection (UMP), we propose a type-aware coding approach. The proposed approach can be used to construct a UMP code with multiple classes of messages, and can also be employed as a finite-length joint source-channel coding (JSCC) where the source statistics is not required at the transmitter. At the transmitter, an information bit sequence is first encoded using a fixed-to-fixed-length type-aware description and then encoded by a given linear block code along with a “free-ride” approach. At the receiver, a type-search decoding algorithm is employed. Numerical results show that, 1) As a UMP coding, the type-aware coding can provide more protection for biased binary sequences; 2) As a finite-length JSCC, the type-aware coding can improve the average error performance for biased sources over the distribution-aware decoding.