Application of Variable-Rate Convolutional Code for Mobile Communications

Abstract

An optimal application method of variable-rate convolutional coding is presented to effectively correspond to the channel environment while optimizing data transmission efficiency. The proposed method can maintain error performance at a required level regardless of the fast fluctuation of received signal envelope. And at the same time, transmission efficiency can be constantly kept by alternatively using R=1/N convolutional code, R=k/n punctured convolutional code, and R=1/2N convolutional code that made by one repetition of R=1/N code symbol according to the channel status report. To verify advanteges of the proposed method, three kinds of codes(R=1/4, 1/2, and 2/3) are applied in adaptive manners. Consequently, about 40% data transmission efficiency is achieved while maintaining the performance of the system at SNR is 10⁻³