Radar Constant-Modulus Waveform Design with Prior Information of the Extended Target and Clutter

Abstract

Radar waveform design is of great importance for radar system performances and has drawn considerable attention recently. Constant modulus is an important waveform design consideration, both from the point of view of hardware realization and to allow for full utilization of the transmitter’s power. In this paper, we consider the problem of constant-modulus waveform design for extended target detection with prior information about the extended target and clutter. At first, we propose an arbitrary-phase unimodular waveform design method via joint transmitter-receiver optimization. We exploit a semi-definite relaxation technique to transform an intractable non-convex problem into a convex problem, which can then be efficiently solved. Furthermore, quadrature phase shift keying waveform is designed, which is easier to implement than arbitrary-phase waveforms. Numerical results demonstrate the effectiveness of the proposed methods.

Efficient Low-PAR Waveform Design Method for Extended Target Estimation Based on Information Theory in Cognitive Radar

“…Considering the signal-dependent clutter, the waveform design methods for target estimation based on MI and MMSE were proposed in [11,12], respectively. It is worth noting that the envelope constraint on the transmitted waveform was not considered in any of those studies, which made it difficult to meet the hardware constraints and maximize the power efficiency [13]. For this reason, unimodular or low peak-to-average power ratio (PAR) waveform is always applied in radar systems [13,14].…”

“…It is worth noting that the envelope constraint on the transmitted waveform was not considered in any of those studies, which made it difficult to meet the hardware constraints and maximize the power efficiency [13]. For this reason, unimodular or low peak-to-average power ratio (PAR) waveform is always applied in radar systems [13,14]. Nevertheless, unimodular waveform may lead to the degradation of waveform performance [15].…”

Designing Waveform Sets with Good Correlation and Stopband Properties for MIMO Radar via the Gradient-Based Method

“…Additionally, when $\lambda \in false(0,1false]$, (14) becomes the criterion for SFW design. Generally, for maximizing the transmitter efficiency and reducing the requirement to the hardware, the unimodular constraint [38] is required in the waveform design. Therefore, the design problem can be formulated as the following minimization problem: $\begin{array}{c}\underset{{false\{{\mathbf{x}}_{m}false\}}_{m=1}^M}{falseprefixmin}{J}_T\hfill \\ \mathrm{s}.\mathrm{t}.\left|x_{m}false(nfalse)\right|=1,n=1,...,N,m=1,...,M.\hfill \end{array}$…”

Optimal Unimodular Sequences Design Method for Active Sensing Systems

“…Since random sequences with low autocorrelation sidelobes can greatly improve the distance resolution of the detection signal, they are widely adopted as modulation sequences in active sensing systems, like radar, communication, proximity fuze, and so on [1][2][3][4]. Moreover, due to the limitations of hardware conditions (such as digital-to-analog converters, power amplifiers), it is usually more desirable to transmit unimodular sequences (i.e., constant modulus) to make full utilization of the transmitter's power [5,6]. So far, the most common modulation sequences applied in practical engineering are the pseudorandom code binary sequences, like m sequence, Gold sequence, chaotic sequence, and so on.…”