The bandwidth efficiency and ability to combat the effects of frequency selective channels are critical issues in the design of wideband wireless digital communications system.

在宽带无线数字通信系统中，影响信息高速传输的最主要的一类干扰是由信道的多径效应所引起的频率选择性衰落。

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In the future broadband wireless communications, there will be two severe challenges to be faced, which are frequency selective fading channels and bandwidth efficiency.

在未来宽带移动通信中，存在两个最严峻的挑战：多径衰落信道和带宽效率。

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