Effect of carrier frequency offset and symbol timing offset on the performance of FMT over time‐frequency selective channels
Effect of carrier frequency offset and symbol timing offset on the performance of FMT over time‐frequency selective channels
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DOI：
10.1002/ett.1544
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发表时间：
2012-08
影响因子：
3.6
通讯作者：
Jing Zheng;Zulin Wang
中科院分区：
文献类型：
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作者：
Jing Zheng;Zulin Wang
本文研究了时频选择性多径衰落信道中滤波多音（FMT）系统中载波频偏（CFO）和符号定时偏移（STO）的影响。该分析基于使用平方根升余弦脉冲的FMT系统。推导了在不同衰落信道下，FMT系统在存在CFO和STO时的性能，并与正交频分复用系统的性能进行了比较。失调会导致滤波器失配，从而降低FMT系统的性能。CFO改变接收机滤波器的幅频特性，而STO改变接收机滤波器的相频特性。在不同的衰落信道下进行了仿真。为了在平坦静态信道上实现20 dB以上的信干比，在正交频分复用系统中，相对于符号持续时间的频率偏移必须小于5%，而在FMT系统中，上限为8%。仿真结果还表明，在时频选择性信道中，FMT系统对频偏不敏感。信号干扰比表达式有助于预测具有单抽头子信道均衡的FMT的误比特率性能。在一定的信道条件下，分析了FMT系统中同步偏移的影响，为同步算法的设计提供了参考。版权所有© 2012约翰威利父子有限公司.
This paper presents the effects of carrier frequency offset (CFO) and symbol timing offset (STO) in filtered multitone (FMT) systems over time and frequency selective multipath fading channels. The analysis is based on an FMT system using a square‐root raised cosine pulse. The performance of FMT systems in the presence of CFO and STO over different fading channels are derived and compared with that of orthogonal frequency division multiplexing systems. The offsets degrade the performance of the FMT systems because they cause filter mismatch. The CFO changes the amplitude frequency characteristic of the receiver filter, while the STO changes the phase frequency characteristic of the receiver filter. The simulations are conducted over different fading channels. To achieve signal‐to‐interference ratio above 20 dB, over a flat static channel, the frequency offset relative to symbol duration must be less than 5% in the orthogonal frequency division multiplexing system, while the upper limit is 8% in the FMT system. The simulation results also show that the FMT system is less sensitive to CFO in time frequency selective channels. The signal‐to‐interference ratio expressions help predict the bit‐error‐rate performance of FMT with single tap subchannel equalization. The analysis also helps synchronization algorithm design after analyzing the synchronization offset effect in FMT systems under certain channel conditions. Copyright © 2012 John Wiley & Sons, Ltd.