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最近几年发展起来的格状编码调制TCM(Trellis-Coded Modulation)技术,将编码与信号星座图的排列作为一个整体考虑,突破了信号调制与信道编码分别实现的传统概念.在信噪比上获得3～6dB 的增益,为超高速数据传输开辟了一条新路.速率为14.4kbps 的格状编码调制器的设计见文献[2].其原理是:在并行输入6bit数据中,将低2位bit 经过卷积码编码器输出3bit,并与未经编码直接输入的高4位bit组成编码器并行输出.将输出端7bit 为一组的信号映射为2~7=128个信号点,以信号点的
The Trellis-Coded Modulation (TCM) technology developed in recent years has considered the arrangement of coding and signal constellation as a whole and has broken through the traditional concepts of signal modulation and channel coding respectively. Gain 3 ~ 6dB gain, has opened up a new road for ultra-high speed data transmission.The design of the trellis-coded modulator with a rate of 14.4 kbps is shown in [2] .The principle is: in the parallel input 6bit data, the low 2 The bit bit is output by the convolutional coder 3 bit and is output in parallel with the upper 4 bits of the uncoded input bit 4. The signals of 7 bits of the output end are mapped into 2 to 7 = 128 signal points, Signal point