论文部分内容阅读
自由度是一个空间复用概念,是在多天线系统中引入的,体现了无线信道对空间资源的利用效率。在认知无线电中,由于主、次网络会相互干扰,从而会降低自由度。本文主要研究的是2?2 X信道(XC:X Channel)和点对点信道(PTP:Point to Point)并存时网络的自由度。研究结论也适合于XC优先于PTP信道的情况。在已知发送端信道状态信息的前提下,基于符号扩展模型,利用渐进干扰对齐方法给出了对应的信号处理方案,并证明当n趋于无穷大时,自由度内界可达5/3。利用传播时延模型示范了其可达性。此外,分析了自由度上界。
Degrees of freedom is a concept of spatial multiplexing introduced in multi-antenna systems, reflecting the efficient use of wireless channels for space resources. In cognitive radio, the primary and secondary networks interfere with each other, which reduces the degree of freedom. This paper mainly studies the degree of freedom of the network when 2 × 2 X channel (XC) and point to point (PTP) coexist. The conclusion is also suitable for the situation that XC takes precedence over PTP channel. On the premise of knowing the channel state information of the transmitting end, a signal processing scheme is given based on the symbolic extension model and using the method of progressive interference alignment, and the inner bound of the degree of freedom can be up to 5/3 when n tends to infinity. The propagation delay model is used to demonstrate its reachability. In addition, the upper bound of degrees of freedom is analyzed.