CAJ | 학술논문

当与时分双工主用户系统共存时，认知无线电系统首先需要识别主用户系统在时间尺度上的传输方向，以便在不同链路上分别设计与执行后续的认知过程，从而优化认知系统的性能。在目前的研究中，均假设认知系统已先验已知主用户系统上下行链路在时间上的交替规律。在普适的认知场景下，该假设并不实际。该文依据双工通信系统上下行发射功率的差异，提出对 TD-LTE 主用户系统在时间尺度上传输方向的识别算法；基于此初步识别结果，进一步提出对 TD-LTE 系统上下行配置类型的识别算法。该方法无需主次系统之间的信息交互，实现简单。仿真表明，通过数个次级用户观察10个左右的TD-LTE帧，即可对其上下行配置类型达到95%以上的识别精度。
당여시분쌍공주용호계통공존시，인지무선전계통수선수요식별주용호계통재시간척도상적전수방향，이편재불동련로상분별설계여집행후속적인지과정，종이우화인지계통적성능。재목전적연구중，균가설인지계통이선험이지주용호계통상하행련로재시간상적교체규률。재보괄적인지장경하，해가설병불실제。해문의거쌍공통신계통상하행발사공솔적차이，제출대 TD-LTE 주용호계통재시간척도상전수방향적식별산법；기우차초보식별결과，진일보제출대 TD-LTE 계통상하행배치류형적식별산법。해방법무수주차계통지간적신식교호，실현간단。방진표명，통과수개차급용호관찰10개좌우적TD-LTE정，즉가대기상하행배치류형체도95%이상적식별정도。
When the cognitive radios are coexisting with time division duplex systems, it should firstly find out the link directions of the primary systems for the separate design and implementation of the followed spectrum sensing and access. However, in the present studies, this information is assumed as prior information of the cognitive radios, which in fact is not practical in common scenarios. In this paper, a method based on the power levels on both links of TD-LTE is proposed to identify the link directions of subframes and the downlink/uplink configuration in the TD-LTE. This method needs not the cooperation between the primary and secondary systems. Simulations show that the method can meet a high accuracy when a few of frames and SUs are participated in the identification.