摘要
移动通信信道是现代通信系统中最为复杂的信道,OFDM(正交频分复用)作为一种有效对抗符号问干扰的高速传输技术备受瞩目。OFDM 技术是一种高效并行多载波传输技术。它将所传送的高速率串行数据分解并调制到多个并行的正交子信道中,从而使每个子信道的码元宽度大于信道时延扩展,可以最大限度地利用频谱资源。OFDM 目前的应用一般限于无线本地局域网(WLAN)和有线电话网上基于现有铜双绞线的非对称高比特率数字用户技术(如 ADSL),而要把它应用于4G 移动通信的物理层,还存在许多挑战。
The mobile communication channel is one of the most complex ones in modem communication system. OFDM, which is robust to ISI （Inter Symbol Interference） in the high speed transmission system, has attracted more attention. OFDM is a parallel multi-carrier technology with high efficiency. After it decomposes the high-speed serial data, it modulates the data into several parallel orthogonal sub-channels. Thus, the symbol width of each sub-channel is greater than the delay of channel, the use of spectrum is maximized. Currently OFDM is only limited for WLAN and the wired telephone network based on ADSL. There are some challenges when it is applied to 4G mobile communication.
出处
《计算机与网络》
2008年第14期35-37,共3页
Computer & Network
