Lan Xiang, Zhang Min, Li Jin-Xing
School of Physics and Optoelectronic Engineering, Xidian University, Xi'an, 710071, China.
Sensors (Basel). 2019 Jun 14;19(12):2696. doi: 10.3390/s19122696.
There are some special merits for the orthogonal frequency division multiplexing (OFDM)chirp waveform as multiple input multiple output (MIMO) signals. This signal has high rangeresolution, good Doppler tolerance, and constant modulus superiority since it exploits a fullbandwidth and is based on chirp signals. The correlation sidelobe peaks level are critical for thedetection requirement of MIMO radar signals, however conventional OFDM chirp signals producehigh autocorrelation sidelobe peaks (ASP) and cross-correlation peaks (CP), which reducesdetection performance. In this paper, we explore the structure of OFDM chirp signals'autocorrelation function and proposed a scheme to reduce the designed signal's ASP by a designingsuitable range of subchirp bandwidth and a segmented transmit-receive mode. Next, we explore asuitable range of interval between the chirp rates of each two signals to reduce the CP. Thesimulation of designed signals verifies the effectiveness of the proposed methods in the reductionof ASP and CP, with the correlation performance being compared with recent relate studies. Inaddition, the multiple signals detection and one-dimensional range image simulation show thegood detection performance of a designed signal in MIMO radar detection.
正交频分复用（OFDM）线性调频波形作为多输入多输出（MIMO）信号具有一些特殊优点。该信号具有高距离分辨率、良好的多普勒容限以及恒模优势，因为它利用了全带宽且基于线性调频信号。相关旁瓣峰值电平对于MIMO雷达信号的检测要求至关重要，然而传统的OFDM线性调频信号会产生较高的自相关旁瓣峰值（ASP）和互相关峰值（CP），这会降低检测性能。在本文中，我们探究了OFDM线性调频信号自相关函数的结构，并提出了一种通过设计合适的子线性调频带宽范围和分段收发模式来降低设计信号ASP的方案。接下来，我们探究每两个信号的线性调频速率之间的合适间隔范围以降低CP。对设计信号的仿真验证了所提方法在降低ASP和CP方面的有效性，并将相关性能与近期的相关研究进行了比较。此外，多信号检测和一维距离像仿真表明了设计信号在MIMO雷达检测中具有良好的检测性能。
