This paper considers practically relevant aspects and advantages of pulse-shaping orthogonal/biorthogonal frequency division multiplexing (OFDM/BFDM) systems. We analyze the intersymbol/intercarrier interference (ISI/ICI) in such systems when they operate over time-varying channels. Two methods for an ISI/ICI-minimizing pulse design are proposed, and efficient FFT-based modulator and demodulato...

This paper presents a design and implementation result of a high-speed, low-complexity four data-path 64point radix-2 FFT/IFFT processor for high-throughput MIMO-OFDM wireless LAN system. The proposed FFT/IFFT processor can provide a higher throughput rate and low hardware complexity by using a four-parallel datapath scheme and a multipath delay feed-back (MDF) structure. The proposed four data...

The novel method for increasing the data transmission throughput in OFDM based Cognitive Radio system was proposed. If only even or odd subcarriers are assigned to input, the symmetrical IFFT output is generated. By using the property of symmetry, only half part of OFDM symbol with even or odd data is transmitted during first half of OFDM symbol duration, another even or odd different data can ...

The Orthogonal Frequency Division Multiplexing (OFDM) system is already used in commercial applications and is capable to deal with Intersymbolic Interference (ISI) caused by multipath channels. This system gained popularity after the application of the Fast Fourier Transform (FFT) and its inverse (IFFT) to modulate the signal in many subcarriers. This paper discusses implementation aspects of ...

In This paper, the bit error rate analysis (BER) and peak signal to noise ratio performance (PSNR) of discrete wavelet transform (DWT)-OFDM system is compared with conventional fast fourier transform (FFT)-OFDM system for colour image transmission, here we use different error correcting codes like Reed Solomon codes, low density parity check codes (LDPC). The transmitted colour image is found t...

In this work, Orthogonal Frequency Division Multiplexing’s (OFDM) principles, implementation design or high-level system architecture and application were reviewed. The condition for orthogonality, frequency spacing between consecutive subcarriers (called spacing) was established analytically with practical instance highlighted. review also covers Fast Fourier Transform (FFT) which serves as a ...

To produce multiple subcarriers orthogonal frequency division multiplexing (OFDM) often require an inverse fast Fourier transform (IFFT).This paper, present the efficient implementation of a pipeline FFT/IFFT processor for OFDM applications. This design adopts a single-path delay feedback style as the proposed hardware architecture. To eliminate the read-only memories (ROM’s) used to store the ...

Orthogonal Frequency division multiplexing is a field that is in vogue and the latest mobile communication technologies have exploited the advantages of the technique. There have been a lot of architectures that have been presented to improve the performance of the OFDM system. The OFDM transceivers employ both Inverse Fast Fourier Transform and Fast Fourier Transform blocks. A variety of archi...

A combined digital linearization and channel estimation scheme is proposed experimentally demonstrated for short-reach intensity-modulation direct-detection (IM/DD) optical Fast-OFDM systems. Known 2PAM-Fast-OFDM sequences are used training a memoryless polynomial based adaptive post-distorter FFT-based in IM/DD 4PAM-Fast-OFDM The 2PAM signals transmitted only over the odd SCs of sequences. Wit...

In wireless communication systems, the design and analysis of an orthogonal frequency division multiplexing (OFDM) system is highly affected by the nonlinear effects of high power amplifier (HPA). The nonlinear effects of HPA reducing the OFDM system performance. OFDM signalling exhibits high peak-to-average power ratio (PAPR) which results in large sensitivity to nonlinear distortion created b...