An improved implementation scheme based on BICM for IBOC-AM

This paper proposes an improved channel coding scheme based on bit-interleaved coded modulation (BICM) for in-band on-channel amplitude modulation (IBOC-AM). It can yield better coding gains than traditional scheme over Rayleigh fading channels. Generally, BICM embedded LDPC code for IBOC (BICM-L) has better coding performances than BICM embedded convolutional codes for IBOC (BICM-C), which has been proved to be an advanced scheme. However, there is a zone named blind-zone existing in the region of SNRs, where the performance gains of BICM-L with high-order modulation are worse than BICM-C. To achieve an improved performance, for the blind-zone, BICM-L is replaced by BICM-C in this improved scheme. Simulation results confirm that, by using the proposed improved scheme, a better performance gains up to 0.3 dB can be achieved for the blind-zone between 4 dB SNR and 5.1 dB SNR, while an additional gains about 4 dB can be achieved in regions of high SNRs.