瑞利多径衰落信道下OFDM/OQAM系统容量分析

系统容量是分析通信系统性能的一个重要指标,提出了正交频分复用/偏移正交幅度调制(OFDM/OQAM)系统在瑞利多径衰落信道中的信道容量均值和方差进行研究。分析得到瑞利信道模型的概率密度函数并推导出任意两个相关瑞利信道间联合概率密度函数,进而得到OFDM/OQAM系统在瑞利信道下的容量均值和方差的数学表达式,式中以系统的子载波数、信道的信噪比和多径数目为参数。通过对系统进行仿真,分析子载波数、信噪比和多径数对系统容量均值和方差的影响。仿真结果表明:系统容量均值与信噪比成正比,与系统子载波数成反比;系统的容量方差由系统的信噪比和信道的多径数共同影响决定。

Capacity of OFDM/OQAM Systems over Multipath Rayleigh-Fading Channels

Capacity is an important indicator in communication systems performance, the capacity of Orthogonal Frequency Division Multiplexing/Offset Quadrature Amplitude Modulation(OFDM/OQAM) system over multipath Rayleigh-Fading channels is thoroughly investigated. Through analysing the probability density function(PDF) of Rayleigh channels model and deducing the alliance of probability density function in two random relevance Rayleigh channels, we get the mathematical expression about the mean and variance OFDM/OQAM system capacity in multipath Rayleigh-Fading channels, which the function of the parameter is related to the number of the subcarriers of an OFDM/OQAM system, the signal to noise ratio(SNR) and the number of multipath. Simulating the system, we analyse the influence of the mean and variance OFDM/OQAM system about the parameter. The result shows that the systems mean is proportional to SNR and inverse proportional to the number of the subcarriers; the systems variance is defined by SNR and the number of multipath.