摘要
为了充分利用瑞克(RAKE)接收机的多径能量利用效果和智能天线(SA)的定向收发作用,研究了RAKE接收机和智能天线的联合使用,提出了基于智能天线的定向二维(2D)RAKE接收机模型,给出了定向2D-RAKE接收机分别在射频、中频和基带的实现框图、工作原理和输出信号表达式,并对它们的性能以及工程实现做了分析讨论。指出基带定向二维RAKE接收机由于可以在基带上通过幅度加权来实现信号的定向收发,其优点是可以利用目前比较成熟的基带信号处理技术,但是由于不能利用相干解调作用来抑制多径干扰(MPI)和多用户干扰(MAI),存在噪声放大问题;射频定向二维RAKE接收机的信噪比增益最大,但工程实现难度较大;中频定向二维RAKE接收机则具有较高的性价比。
To make full use of the advantage of both RAKE receiver and smart antenna （SA）, a novel 2D directional RAKE receiver, is proposed by combining traditional RAKE and smart antenna. For the 2D directional RAKE receiver, we first present the basic principle of SA with a simple physical model, based on which three different implementation schemes of 2D directional RAKE receiver, radio fre- quency implementation scheme, intermediate frequency implementation scheme and baseband implementation scheme are proposed as well as the study of the expres- sions of output signals and the analysis of performance. The analysis results show that the scheme of the intermediate frequency has the highest performance cost ratio, by which the multi-path effect can be restrained as well as the perfect directional transmitting/receiving. For baseband implementation scheme, though the beam forming can be realized by using the technique of baseband signal amplitude weighting, the gain of signal interference ratio changes along with the direction of arrival （DOA） because the technique of coherent demodulation is disable in this implementation scheme sometimes, which results in the noise amplification and the fluctuation of performance. The radio frequency implementation scheme performances well, but it is hard to realize in engineering.
出处
《电波科学学报》
EI
CSCD
北大核心
2011年第3期501-508,共8页
Chinese Journal of Radio Science
基金
国家自然科学基金(61071090)
江苏省普通高校研究生科研创新计划(CX10B_184Z)
国家973课题(2007CB310607)
