# Coexistence of MIMO Radar and FD MIMO Cellular Systems with QoS Considerations

## TL;DR

This paper investigates spectrum sharing between MIMO radar and full-duplex MIMO cellular systems, proposing joint transceiver design and waveform projection techniques to optimize radar detection probability while maintaining user QoS.

## Contribution

It introduces a novel joint transceiver design and waveform projection method for spectrum sharing between MIMO radar and FD MIMO cellular systems, balancing detection performance and QoS.

## Key findings

- Spectrum sharing is feasible with trade-offs in system performance.
- The proposed design improves radar detection probability under QoS constraints.
- Interference mitigation effectively maintains cellular system performance.

## Abstract

In this work, the feasibility of spectrum sharing between a multiple-input multiple-output (MIMO) radar system (RS) and a MIMO cellular system (CS), comprising of a full duplex (FD) base station (BS) serving multiple downlink and uplink users at the same time and frequency is investigated. While a joint transceiver design technique at the CS's BS and users is proposed to maximise the probability of detection (PoD) of the MIMO RS, subject to constraints of quality of service (QoS) of users and transmit power at the CS, null-space based waveform projection is used to mitigate the interference from RS towards CS. In particular, the proposed technique optimises the performance of PoD of RS by maximising its lower bound, which is obtained by exploiting the monotonically increasing relationship of PoD and its non-centrality parameter. Numerical results show the utility of the proposed spectrum sharing framework, but with certain trade-offs in performance corresponding to RS's transmit power, RS's PoD, CS's residual self interference power at the FD BS and QoS of users.