The performance improvement of UEP code with interleaver

In many applications of digital communication engineering, the bits of the data sequence transmitted do not have equal significance. To seek a more reliable information transmission, some unequal error protection (UEP) coding schemes have been devised. In this paper, however, we do not suggest a new UEP coding scheme, instead, through intimate combination of quantizer, interleaver, and the best convolutional code (CC) or trellis-coded modulation (TCM), the UEP capability can be achieved. Moreover, to investigate the performance of the proposed UEP coding scheme, we deduce the bit error rates of the corresponding encoder input ports from the transfer function of the encoder. The transfer function is derived based on the state diagram, such that the UEP capability of the encoder can be proved. Finally, from the simulation results we find that the mean square error between the original quantized signal and the received quantized signal can be reduced when the presented method is employed compared to the CC or TCM without the interleaver.