Peak reduction in OFDM using second-order cone programming relaxation

Abstract

In this paper, we address the problem of peak-to-average power ratio (PAPR) reduction in orthogonal frequency-division multiplexing (OFDM) systems. We formulate the problem as an error vector magnitude (EVM) optimization task with constraints on PAPR and free carrier power overhead (FCPO). This problem, which is known to be NP hard, is shown to be approximated by a second-order cone programming (SOCP) problem using a sequential convex programming approach, making it much easier to handle. This approach can be extended to the more general problem when PAPR, EVM, and FCPO are constrained simultaneously. Our performance results show the effectiveness of the proposed approach, which allows good performance with lower computational complexity and infeasibility rate than state-of-the-art PAPR-reduction convex approaches. Moreover, in the case when all the three system parameters are constrained simultaneously, the proposed approach outperforms the convex approaches in terms of infeasibility rate, PAPR, and bit error rate (BER) performances.

Peak‐to‐average power ratio reduction in multiple‐input multiple‐output orthogonal frequency‐division multiple access systems using geodesic descent method

“…In general, the PAPR minimisation of OFDM signals is a complex optimisation problem. To overcome these difficulties, convex optimisation methods were recently proposed as an efficient tool for reducing the PAPR of OFDM signals [15–19]. Although allowing substantial complexity gains, these techniques are still too complex for practical implementations, since the number of subcarriers is usually in the order of several hundreds, which means an optimisation problem with a large number of variables.…”