水声信道是一个时变的双扩散信道,不仅会引起传输信号的时频扩展,而且会造成严重的信息损失。由于滤波器组多载波/交错正交幅度调制(Filter Bank Based Multicarrier/Offset Quadrature Amplitude Modulation, FBMC/OQAM)系统可通过改...水声信道是一个时变的双扩散信道,不仅会引起传输信号的时频扩展,而且会造成严重的信息损失。由于滤波器组多载波/交错正交幅度调制(Filter Bank Based Multicarrier/Offset Quadrature Amplitude Modulation, FBMC/OQAM)系统可通过改变发送信号的成型脉冲来减小时频扩展带来的符号干扰和子载波干扰,因此更适合快速时变的水下声信道。为了降低现有成型脉冲设计算法的优化难度,提出了一种快速且易于实现的成型脉冲设计方法,该方法根据信道时频统计特性对扩展高斯函数(Extend Gaussian Function, EGF)进行了优化,实现了期望信号能量最大化,并在时域符号间加入适当的保护间隔,进一步增强了抗多途干扰的能力。仿真结果表明,无论在高频散信道还是在低频信道下,相比于其它成型脉冲算法,该算法在降低计算量的同时,改进了的FBMC/OQAM系统的传输性能,误码率降低了2～3 dB。展开更多
The performance of an OFDM/OQAM system under phase noise is analyzed. The analysis helps to direct the design of low cost tuners through specifying the required phase noise characteristics. Discrete time formulation o...The performance of an OFDM/OQAM system under phase noise is analyzed. The analysis helps to direct the design of low cost tuners through specifying the required phase noise characteristics. Discrete time formulation of OFDM/OQAM is first derived with the square root raised cosine (SRRC) filter as the pulse-shaping filter. Then the effect of multiplicative phase noise is equivalently represented as additive white Gaussian noise (AWGN), the variance of which is given analytically. We can observe that the same result as OFDM/QAM system is derived. Lastly, all the analytical results are verified by the bit error rate (BER) degradation through Monte Carlo simulation.展开更多
Compared to OFDM systems with cyclic prefi x, fi lterbank multicarrier with offset quadrature amplitude modulation(FBMC/OQAM) system is considered as an alternative technology for next generation wireless communicatio...Compared to OFDM systems with cyclic prefi x, fi lterbank multicarrier with offset quadrature amplitude modulation(FBMC/OQAM) system is considered as an alternative technology for next generation wireless communication systems. However, FBMC systems suffer from intrinsic imaginary interference caused by the real-fi eld orthogonality destruction when passing through complex-valued fading channels. By analyzing the transmultiplexer's response of FBMC/OQAM systems, in this paper, a simple conjugated transmission scheme is proposed for FBMC/OQAM systems. Following the specific conjugation design, the intrinsic imaginary interference including the intrinsic inter-symbol and the inter-carrier interference can be eliminated at the receiver side through linear signal processing operation. Meanwhile, the proposed conjugated transmission scheme is able to obtain extra linear combination diversity gains for improving the systematic performance of FBMC/OQAM. Simulation results show that the proposed scheme is more efficient than conventional methods, especially in practical application scenarios with large Doppler spread caused by high-speed movement.展开更多
文摘The performance of an OFDM/OQAM system under phase noise is analyzed. The analysis helps to direct the design of low cost tuners through specifying the required phase noise characteristics. Discrete time formulation of OFDM/OQAM is first derived with the square root raised cosine (SRRC) filter as the pulse-shaping filter. Then the effect of multiplicative phase noise is equivalently represented as additive white Gaussian noise (AWGN), the variance of which is given analytically. We can observe that the same result as OFDM/QAM system is derived. Lastly, all the analytical results are verified by the bit error rate (BER) degradation through Monte Carlo simulation.
基金supported by the MOST Program of International S&T Cooperation(Grant No.2016YFE0123200)National Natural Science Foundation of China(Grant No.61471100/61101090/61571082)+1 种基金Science and Technology on Electronic Information Control Laboratory(Grant No.6142105040103)Fundamental Research Funds for the Central Universities(Grant No.ZYGX2015J012/ZYGX2014Z005)
文摘Compared to OFDM systems with cyclic prefi x, fi lterbank multicarrier with offset quadrature amplitude modulation(FBMC/OQAM) system is considered as an alternative technology for next generation wireless communication systems. However, FBMC systems suffer from intrinsic imaginary interference caused by the real-fi eld orthogonality destruction when passing through complex-valued fading channels. By analyzing the transmultiplexer's response of FBMC/OQAM systems, in this paper, a simple conjugated transmission scheme is proposed for FBMC/OQAM systems. Following the specific conjugation design, the intrinsic imaginary interference including the intrinsic inter-symbol and the inter-carrier interference can be eliminated at the receiver side through linear signal processing operation. Meanwhile, the proposed conjugated transmission scheme is able to obtain extra linear combination diversity gains for improving the systematic performance of FBMC/OQAM. Simulation results show that the proposed scheme is more efficient than conventional methods, especially in practical application scenarios with large Doppler spread caused by high-speed movement.
