An improved channel coding scheme based on turbo-BICM for IBOC-AM

Hybrid in-band on-channel (IBOC) broadcasting system is a scheme of digital audio radio, which could transmit analog AM and digital audio simultaneously. In IBOC systems, broadcasters transmit signals within the allocated channel bands, thus the bandwidth assigned for digital audio transmission is very limited. BICM can improve BER performance over Rayleigh fading channels without bandwidth expansion, thus it is widely used in mobile-radio channels. It has been found that by using BICM, an IBOC-AM broadcasting system can yield a better coding gain. Turbo-BICM, the combination of turbo encoder and BICM, is known as a remarkable scheme with high coding diversity and high flexibility. In this paper, an improved channel coding scheme based on turbo-BICM is proposed to achieve better reliability compared with the conventional IBOC system. Simulation results show that the proposed scheme can effectively improve the receiving performance of an AM IBOC system. When BER is below 10^-5, the improved coding scheme can achieve more than 4 dB code gains over Rayleigh fading channels.