基于频分多址的多用户OFDM通信雷达一体化方案

Multiuser OFDM RadCom Scheme Based on FDMA

通信雷达一体化(RadCom)被认为是下一代通信技术的重要研究方向,受到了学术界和工业界的广泛关注。研究了基于频分多址(FDMA)的多用户OFDM RadCom方案,其关键问题在于多用户子载波分配方式。不同的子载波分配方式会导致雷达距离处理出现不同的旁瓣水平,从而影响雷达的测距性能,在子载波采用连续分配和随机分配方式的情况下,各用户在雷达距离处理时会出现明显的旁瓣,雷达测距性能退化严重。为了找到适当的子载波分配方式,使得各用户的雷达距离处理的旁瓣水平尽可能低,以距离观测窗内的综合旁瓣水平作为代价函数,发现在用户数受限的情况下,子载波采用等间隔分配方式时,代价函数取得最小值,所有用户的旁瓣水平在距离观测窗内最低,各用户都能够有效地实现雷达探测功能。最后,在车联网(IoV)场景下,对不同的子载波分配方式进行仿真和对比,验证了子载波等间隔分配的有效性。

Fusion of radar and communication(RadCom)is regarded as an important research direction of the next generation of communication technology,which has attracted extensive attention from academia and industry.In this paper,a multiuser orthogonal frequency division multiplexing(OFDM)RadCom scheme based on frequency division multiple access(FDMA)is studied.The key problem lies in the multiuser subcarrier allocation.Different subcarrier allocation methods will lead to different sidelobe levels in range processing,which will affect the ranging performance of radar;when subcarriers are continuously assigned and randomly assigned,there will be obvious sidelobe in range processing of each user,and the performance of radar ranging will be degraded seriously.In order to find a proper subcarrier allocation method that makes the sidelobe level of radar range processing of each user as low as possible,we take the integrated sidelobe level in the range observation window as a cost function.We find that when the number of users is limited and the subcarriers are allocated with equal intervals,the cost function achieves the minimum value,and the sidelobe level of all users is the lowest in the range observation window,so all users can effectively realize the radar detection function.Finally,in the internet of vehicles(IoV)scenario,different subcarrier allocation methods are simulated and compared to verify the effectiveness of the equal interval subcarrier allocation method.