Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing technology is an advanced transmission technique for wireless communication systems. In this paper, the 64 point pipeline FFT/IFFT processor is introduced for efficient implementation of OFDM architecture. The IFFT processor is used to modulate the subcarrier in transmitter section and FFT processor demodulate the subcarr...

Since an FFT-based speech encryption system retains a considerable residual intelligibility, such as talk spurts and the original intonation in the encrypted speech, this makes it easy for eavesdroppers to deduce the information contents from the encrypted speech. In this letter, we propose a new technique based on the combination of an orthogonal frequency division multiplexing (OFDM) scheme a...

This article examines the performance of Wavelet based Multi-User MIMO OFDM (MUMIMO WOFDM) systems and a comparison is made with classical FFT based multiuser MIMO OFDM system. Wavelet analysis has some strong advantages over fourier analysis, as it allows a time-frequency domain operation, allowing optimal resolution and flexibility. Wavelets have been satisfactorily applied in almost all the ...

The FFT processor is a very important component in Orthogonal Frequency Division Multiplexing(OFDM) communication system. In this paper, we propose an efficient variable-length radix-8/4/2 FFT architecture for OFDM systems. The FFT processor is based on radix-8 FFT algorithm and also supports radix-4 or radix-2 FFT computation. The pipelined radix-8/4/2 butterfly unit computes radix-8 FFT algor...

Growth in technology has led to unprecedented demand for high speed architectures for complex signal processing applications. In 4G wireless communication systems, bandwidth is a precious commodity, and service providers continuously met with the challenge of accommodating more users with in a limited allocated bandwidth. To increase data rate of wireless medium with higher performance, OFDM (o...

At the 60 GHz band a massive amount of spectral space (5 GHz) has been allocated unlicensed worldwide for dense wireless local communications. OFDM has gained much popularity in the field of wireless communication because of its ability to transfer the data at higher rate, high bandwidth efficiency and robustness to multipath and delay.The BER performance of conventional FFT-OFDM system is comp...

Mobile WiMAX (Worldwide Interoperability for Microwave Access) or 802.16e standard was ratified by the IEEE in late 2005 as a potential to emerge as a real viable competitor to existing 3G technologies. Mobile WiMAX uses an OFDMATM technology called 1K-FFT. Orthogonal Frequency-Division Multiple Access (OFDMA) is a multi-user version of the popular Orthogonal frequency-division multiplexing (OF...

--In OFDM systems, Fast Fourier transform (FFT) is used for frequency translation, and recently Discrete Wavelet Transform (DWT) has replaced FFT for frequency translation. 16-QAM (Quadrature amplitude modulation) scheme has been used in the OFDM system for both DWT and FFT based models. This work presents a modified OFDM system that is based on a low complexity interleaving process which is ap...