A low complexity SI sequence estimator for pilot-aided SLM–OFDM systems

Abstract

Selected mapping (SLM) is a well-known method for reducing peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. However, as a consequence of implementing SLM, OFDM receivers often require estimation of some side information (SI) in order to achieve successful data recovery. Existing SI estimation schemes have very high computational complexities that put additional constraints on limited resources and increase system complexity. To address this problem, an alternative SLM approach that facilitates estimation of SI in the form of phase detection is presented. Simulations show that this modified SLM approach produces similar PAPR reduction performance when compared to conventional SLM. With no amplifier distortion and in the presence of non-linear power amplifier distortion, the proposed SI estimation approach achieves similar data recovery performance as both standard SLM–OFDM (with perfect SI estimation) and also when SI estimation is implemented through the use of an existing frequency-domain correlation (FDC) decision metric. In addition, the proposed method significantly reduces computational complexity compared with the FDC scheme and an ML estimation scheme

Performance of modified and low complexity pulse shaping filters for IEEE 802.11 OFDM transmission

“…The complexity of the MFEXP and BTMFEXP filters are analysed by computing the number of Real Multiplications, RMs and Real Addition, RAs for the high and low complexity forms of the filters. Using 'taylortool' function in Matlab TM , it was verified that the first five terms in a Taylor Series representation is enough to produce the same results as implementing trigonometric functions (Adegbite, McMeekin, & Stewart, 2016). The sine terms and cosine terms when expanded up to the first five terms give the computations below (Adegbite et al, 2016).…”

Low-Complexity PAPR Reduction Scheme Combining Multi-Band Hadamard Precoding and Clipping in OFDM-Based Optical Communications

“…Several PAPR reduction techniques have been proposed for wireless communication systems [11][12][13][14][15][16][17][18]. In general, these techniques can be broadly categorized into signal distortion, distortionless, and coding schemes.…”

“…However, these signal processing schemes result in both in-band distortion and out-of-band high frequency components, which further degrades the bit error rate (BER) performance and reduces the spectral efficiency. Selective mapping (SLM), and partial transmit sequence (PTS) are typical distortionless schemes [16][17][18] that improve the PAPR distribution statistically and provide pretty good PAPR performance. However, they all have very high computational complexities and require the receivers to know the side information to retrieve the original data blocks.…”