Waveform Generation for a MIMO Radar

Abstract

Multiple-input multiple-output (MIMO) radars achieve improved performance by the simultaneous transmission and reception of waveforms from different locations. Orthogonality of the transmitted waveforms is a requirement for allowing waveform separation at the receiver. In addition, signals with a large BT- product (e.g. coded signals) could be transmitted to achieve high Signal to Noise Ratio (SNR) due to pulse compression. This helps to radiate a larger amount of average power as a result of which range resolution (larger bandwidth) and detection capability improves. These techniques are indeed combined in Space – Time coded active antenna systems, where multiple codes are simultaneously transmitted through the different elements or sub-arrays of an active antenna. My thesis, "Waveform generation for a MIMO Radar" involves the design and implementation of the Arbitrary Waveform Generation (AWG) Block for a multi-channel transmitter of such a MIMO radar test bed. The 8-channel AWG block is developed on an FPGA platform. Besides the AWG, there are the RF and antenna blocks in the multi-channel transmitter. The synchronization of the multiple transmitters is the essential pre-requisite to develop the system. Similarly the individual channels of the system need to be characterized by measuring the errors within the system. The test-bed will be used as a platform for generating and testing different waveforms (binary codes, multi-phase codes, complementary waveforms, etc.) that can provide the radar with required resolutions in range, space, velocity. This could in turn be used to analyze these signals using their ambiguity function in case of space-time adaptive processing. Finally, the influence of the errors on the ambiguity functions for colored waveform transmission could be studied.