In this paper, the performance of Dicrete Wavelet Transform (DWT) based Multi-user MIMO-OFDM is compared with the performance of FFT based MIMO-OFDM system. Wavelet based OFDM has lot of advantages compared to the FFT based OFDM. There is no need for cyclic prefix, flexibility and optimal resolution. Wavelets existed suitably in almost all the arenas of wireless communication schemes with OFDM ...

Abstract: Recently, we proposed OFDM combined with time division multiplexing (OFDM/TDM) to alleviate the high peak-to-average power ratio (PAPR) problem of OFDM. To further reduce the PAPR, amplitude clipping can be used. However, the bit error rate (BER) performance degrades and the out-of-band (OoB) power spectrum grows. Therefore, filtering is necessary to suppress the OoB power growth, but...

Recently, coherent optical OFDM (CO-OFDM) has been proposed for optical networks to combat chromatic dispersion. CO-OFDM system has been successfully processed and recovered for transmitted signals without optical chromatic dispersion compensation. However, in optical links, the available optical power is limited due to fiber nonlinearity, and power consumption. As previously reported, we focus...

Light Fidelity (LiFi) technology has gained attention and is growing rapidly today. Utilizing light as a propagation medium allows LiFi to promise wider bandwidth than existing Wireless (WiFi) enables the implementation of cellular improve utilization. In addition, very attractive because it can utilize lighting facilities consisting light-emitting diodes (LEDs). A system that uses intensity mo...

Abstract Non-orthogonal multiple access (NOMA) is expected to be used in beyond fifth-generation (B5G) and sixth-generation (6G) mobile networks support ultra-massive connectivity. Since the two preceding generations orthogonal frequency division multiplexing (OFDM), NOMA combined with OFDM. Unfortunately, OFDM signal suffers from a high peak average power ratio (PAPR) that limits its performan...

The fractional Fourier transform (FRFT), which is a family of linear transformations generalizing the classical transform, has been used in fields filter design, signal processing, phase retrieval, and pattern recognition due to its unique properties. FRFT can be interpreted as decomposition terms chirps. In this paper, for first time, best our knowledge, we introduce an optical (OFRFT)-based o...

the destructive impact of fading environments and also bandwidth limitations are two main challenges which communication is dealing with them. these challenges can affect on the growth of wireless communication and even cause reliable communications and high data rate to be prevented. thus, ofdm (orthogonal frequency division multiplexing) modulation by using of fast calculation hardwares such ...

Abstract This paper aims to improve the channel estimation (CE) in indoor visible light communication system. The proposal of this deals with a system that depends on comparison between Deep Neural Network (DNN), Yolo v3, and Kalman filter (KF) algorithm, for two optical modulation techniques; asymmetrically clipped optical-orthogonal frequency-division multiplexing (ACO-OFDM) direct current fr...