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Two gains play key roles in recently developed‎ MIMO ‎wireless communication systems‎: ‎"spatial diversity‎" ‎gain and "spatial multiplexing‎" ‎gain‎. ‎The diversity gain refers to the capability to decrease the error rate of the MIMO channel‎, ‎while the multiplexing gain implicitly refers to the amount of increase in the capacity of the MIMO channel‎. ‎It has been shown that there is a fundamental tradeoff between these two types of gains‎, ‎meaning interplay between increasing reliability (via an increase in the diversity gain) and increasing data rate (via an increase in the multiplexing gain)‎. ‎On the other hand‎, ‎recently‎, ‎MIMO radars have attracted much attention for their superior ability to enhance the system's performance‎. ‎As a MIMO system‎, ‎it is expected that the mentioned diversity-multiplexing tradeoff exists in a MIMO radar‎, ‎too‎. ‎In this paper‎, ‎this tradeoff is studied and verified in MIMO radars with widely separated antennas‎. ‎In more details‎, ‎it will be shown that increasing dependency between transmit-receive links results in higher diversity gain and lower multiplexing gain‎, ‎and vice versa‎. ‎Then‎, ‎the optimal tradeoff is introduced‎, ‎i.e.‎, ‎the conditions that the MIMO radar system should have‎, ‎so that the diversity-multiplexing tradeoff is at its optimum point‎, ‎are driven‎.

This paper studies the placement of antennas in presence of mountains for widely separated multiple-input multiple-output (MIMO) radar. One of the challenges in this configuration is proper placement of the receive antennas in order to achieve good performance. We derived Neyman-Pearson decision rule for target detection. Via several scenarios we show that proper placement of receivers can provide better performance.

There has been much interest, recently, towards exploiting the Multiple-Input Multiple-Output (MIMO) technique in radar. It is shown that using multiple antennas at transmit and receive sides can improve the performance of the system. However, in order to analyze the system's performance, its ambiguity function, i.e. the ambiguity function of a MIMO radar, is needed to be defined. In this paper, beginning from the information theoretic definitions, we derive such function, specifically for a MIMO radar with widely separated antennas.

Using multiple illuminators of opportunity at the transmit side and multiple antennas at the receiver side in a passive coherent location (PCL) scheme is expected to improve the detection performance. However, in such multiple-input multiple-output (MIMO) configuration choosing the position of the receivers is an obstacle that can have significant influence on the resulting performance. In this study, the authors consider the case of digital video broadcast (DVB)-T stations as non-cooperative transmitters and introduce a procedure based on the probability of missed detection to properly place receive antennas in a MIMO digital video broadcasting (DVB)-T based PCL configuration.