Coded Modulation Scheme with CPPC Codes for FM IBOC Broadcasting

Hybrid in-band on-channel (IBOC) broadcasting system is a method of digital audio radio, which could transmit analog FM and digital audio simultaneously. Due to the existence of fading and interference in FM bands, however, the signal receiving for the hybrid IBOC system is very challenging. In this work, a type of coded modulation scheme was proposed in hybrid in-band on-channel system, which combines complementary punctured-pair convolutional (CPPC) codes and BICM with iterative decoding (BICM-ID). The CPPC codes can largely resist the first adjacent-channel interference, the noise and fading. TCM, a bandwidth-efficient approach, primarily is considered for Gaussian channels. While a new scheme of BICM can be used to provide excellent performance over both Gaussian and fading channels with iterative decoding (ID). By using BICM-ID, an FM IBOC broadcasting system can yield a better coding gain over complex Rayleigh fading channels without bandwidth expansion. Through the analysis and simulation, results show that the proposed scheme can effectively improve the receiving performance of an FM IBOC system.