With the advent of new high data rate wireless applications, as well as growth of existing wireless services, demand for additional bandwidth is rapidly increasing. Existing “command-and-control” spectrum allocations defined by government regulatory agencies, such as federal communications commission (FCC), prohibit unlicensed access to licensed spectrum, constraining them instead to several he...

We discuss the influence of random-and periodic impulse noise on narrowband (< 500 kHz frequency band) Power Line Communications. We start with random impulse noise and compare the properties of the measured impulse noise with the common theoretical models like Middleton Class-A and Mixed Gaussian. The main difference is the fact that the measured impulse noise is noise with memory for the narr...

In this paper, a new VLSI based Radix-4 FFT architecture is developed by combining the mixed radix and pipelining architectures. Proposed architecture named as “Radix-4 Combined Single Path Delay Feedback (SDF) Multipath Delay Commutator (MDC) FFT”. As the name itself, design of proposed FFT architecture is designed with the help of both SDF and MDC data flow structures. Both SDF and MDC archit...

This paper presents a high speed and low complexity modified radix-2 512-point Fast Fourier transform (FFT) architecture using an eight data-path pipelined approach for high rate wireless personal area network applications. A novel modified radix-2 FFT algorithm that reduces the hardware complexity is proposed. This method can reduce the number of complex multiplications and the size of the twi...

This paper proposes a novel concept of adjusting the hardware size in a multi-carrier code division multiple access (MC-CDMA) receiver in real time as per the channel parameters such as delay spread, signal-to-noise ratio, transmission rate, and Doppler frequency. The fast Fourier transform (FFT) or inverse FFT (IFFT) size in orthogonal frequency division multiplexing (OFDM)/MC-CDMA transceiver...

Orthogonal Frequency Division Multiplexing (OFDM) is gaining popularity for high data rate communication systems. We propose the use of adaptive beamforming for interference rejection in OFDM systems, due to its advantages over equalization. An adaptive beamformer uses the concept of spatial filtering to direct the antenna beam towards the desired signal/transmitter and place a null towards the...

High Peak – to – average power ratio (PAPR) of transmitted signals is a major shortcoming for multicarrier modulation system such as orthogonal frequency division multiplexing (OFDM) and wavelet packet modulation (WPM). This paper introduces a novel OFDM system base on dual – tree complex wavelet transform (DT-CWT). In the proposed scheme, DTCWT is used in the place of fast Fourier transform (F...