仿真研究了整數(shù)倍和分?jǐn)?shù)倍定時(shí)誤差對(duì)于預(yù)均衡OFDM系統(tǒng)的性能影響，結(jié)果表明：定時(shí)誤差將造成解調(diào)數(shù)據(jù)的相位旋轉(zhuǎn), 并導(dǎo)致預(yù)均衡系統(tǒng)性能的快速下降，其程度由系統(tǒng)的子載波數(shù)和誤差精度等因素決定；仿真顯示，在QPSK，1/3Turbo編碼，90 ms交織，子載波數(shù)4 096，信道模型為ITU RM.1225 車載30 km/h的條件下，每當(dāng)誤差增加1/16的歸一化定時(shí)誤差，性能下降約1 dB。
關(guān) 鍵 詞 預(yù)均衡OFDM; 預(yù)均衡因子; 定時(shí)誤差; 相位旋轉(zhuǎn)因子

Abstract This paper investigated the impact of the timing error on the receiver BER performance in the pre-equalization OFDM systems through simulations. The results showed that the timing error would bring on the phase rotation of demodulation data, and degrade the system performance critically. So it must be revised by assistant methods. The timing error and the number of sub-carriers together decide the degradation. Simulations showed that the performance would fall down 1 dB every 1/16 normalized timing error.
Key words pre-equalization OFDM; pre-equalization factor; timing error; phase rotation coefficient