带内同频道数字音频广播关键技术进展

基于编码正交频分复用的数字音频广播(DAB)具有鲁棒性高和激光唱盘(CD)音质等优良性能。带内同频道(IBOC)制式的DAB能够在已有的模拟广播频道内同播模拟和数字两种信号，完全兼容现有的模拟接收机，以较低成本实现向全数字化DAB的平滑过渡。作者论述了FM IBOC DAB的频谱分析，综述了混合模式FM IBOC DAB的发射(接收)机的基本结构和感知音频编码、前向纠错编码、OFDM、第一邻频道干扰消除、时间延迟分集和音频混合等关键技术，提出了发展我国的 IBOC DAB的一些建议。

Progress on key techniques of in-band on-channel digital audio broadcast

A Digital Audio Broadcasting(DAB) system, which is based on advanced technique of Coded Orthogonal Frequency Division Multiplexing (COFDM), can provide improved performance of high robustness and virtual CD-like quality. In-Band On-Channel(IBOC) digital audio systems have the capability of simultaneously transmitting both analog and digital signals (in hybrid mode)within the allocated channel mask, allowing full compatibility with existing analog receivers, and will accomplish smooth transition from analog broadcasting to all-digital mode DAB at low cost. The authors analyze the spectrum of Frequency Modulation (FM) IBOC DAB, and presents basic structures of FM IBOC DAB transmitting system and receiver, introducing key technologies of Perceptual Audio Coder(PAC), Forward Error Coding(FEC), OFDM, First-Adjacent Canceling(FAC), Time Diversity Delay (TDD)and Audio Blend(AB). By careful comparison and analysis, some advice on development of Chinese IBOC DAB is given.