Abstract: A high-performance DVB-C Quadrature Amplitude Modulation（QAM） demodulator has been presented.By adopting optimal demodulation algorithm and optimizing VLSI implementation architecture，this demodulator achieves high performance at low hardware costs.It supports 4/16/32/64/128/256QAM constellations with symbol rate ranging from 1 MSps to 7 MSps.The demodulator features large carrier offset acquisition range（±700 kHz） and high sensitivity.Experimental results demonstrate the robustness of the proposed demodulator.

Key words: QAM demodulator, VLSI implementation, carrier recovery, adaptive equalization

摘要： 提出了一种适用于DVB-C标准的高性能QAM解调器。通过采用改进的解调算法并优化其VLSI实现结构，该设计在现场测试中不仅取得良好的性能并且节约了硬件资源。该解调器支持4/16/32/64/128/256QAM六种调制模式，符号率1～7 MSps范围内连续可调，具有高灵敏度以及可捕获最大达±700 kHz的载波频偏。实现结果表明该文设计的解调器非常适合于低成本的有线电缆系统。

关键词: QAM解调器, VLSI实现, 载波恢复, 自适应均衡