The overlapping factor has a vital role in determining the optimum bandwidth utilization and the desired side band suppression. In this paper, we review one of the filter bank multicarrier technique-staggered multi tone modulation, discuss its efficient implementation in polyphase form and compare between several performance parameters of the same. We also discuss the role of overlapping factor in staggered multi tone modulation systems. We describe a low complexity procedure for generation of the required overlapping factors based on frequency sampling method. Our simulations describe the effectiveness of the optimum value selection for overlapping factor in a staggered multi tone modulation system. The proposed system is theoretically found to be compatible with the Long Term Evolution standards. The performance evaluation of the proposed system in ideal conditions emphasizes about the reduction in spectrum leakage in sidebands of the staggered multi tone modulation system, along with a little increase in system complexity.

This paper presents a method for the design of two-channel quadrature mirror filter (QMF) banks with linear phase in frequency domain. Low-pass prototype filter of the QMF bank is implemented using polyphase decomposition. Prototype filter coefficients are optimized to minimize an objective function using eigenvalue-eigenvector approach without matrix inversion. The objective function is formulated as a weighted sum of four terms, pass-band error and stop-band residual energy of low-pass analysis filter, the square error of the overall transfer function at the quadrature frequency and amplitude distortion of the filter bank. The simulation results clearly show that the proposed method requires less computational efforts in comparison to the other state-of-art existing design methods.

Wireless Sensor Networks (WSNs) incorporate smart antennas for information propagation to offer connected coverage with reduced interference. This paper presents an omni directional antenna assisted scheme for WSNs to reduce network redundancy besides offering connected coverage. The directivity of an omni directional antenna outfitted on a sink node is exploited to reduce network redundancy and at the same time the connectivity of sensor nodes with the sink node is retained. The relationship between lobe count, beam width, rotation angle and directivity of an omni directional antenna in context of sensor networks is also discussed. Simulation results show a significant reduction in overall network redundancy if the rotation angle of the omni directional antenna fitted on the sink node is minimized from 360° to 30°.