随着军事通信的应用需求迅速扩展,如何有效地在信源端对语音信号进一步压缩。并且在复杂信道条件下实现高质量的低速率语音编码技术是一个重要研究方向。以MBE语音编码模型为基础,提出了一种改良算法,即在编码端利用信源冗余度,将对语音合成质量影响较大的参数进行检纠错保护,并在解码端采用谐波增强以改善终端语音合成质量。测试数据表明,在1%-3%的信道误码条件下,PESQ评分平均提高了近14%。
With the development of military communication and mobile communication, the researches of source coding on low-bit rate and high performance in complex channel condition attract more and more attention. A novel speech coding algorithm is proposed based on MBE(Multi-Band Excitation). The algorithm protects important parameters by exploiting the redundancy of information source and adopts harmonic enhancement for speech synthesis. With no extra bandwidth consumption, the performance of speech coding in anti channel-error-code and synthesis has improved significantly. Experiments show that, in the condition of channel error rates ranging from 1% to 3%, the PESQ score has improved about 14% on average.