Presently, digital signal process strategies are wide studied and varied DSP primarily based schemes are appointive for next-generation passive optical network (PON). A hybrid technique is projected which mixes time-division-multiplexing (TDM) design with advanced DSP strategies to attain high spectrum-efficiency colorless transmission. Orthogonal frequency division multiplexing (OFDM) with fre...

Metasurfaces are artificially engineered two-dimensional materials composed of sub-wavelength meta-atoms, which have shown unprecedented capabilities in manipulating the amplitude, phase, frequency, and polarization states electromagnetic waves. Specifically, control can be attained via suitable anisotropic, linear, time-invariant designs, while frequency conversion is realized nonlinear or tim...

We present the joint maximum likelihood (ML) symbol-time and carrier-frequency offset estimator in orthogonal frequency-division multiplexing (OFDM) systems. Redundant information contained within the cyclic prefix enables this estimation without additional pilots. Simulations show that the frequency estimator may be used in a tracking mode and the time estimator in an acquisition mode.

In this paper, we present a data-based method for simultaneous Maximum Likelihood (ML) symbol timing and carrier-frequency offset estimation in Orthogonal frequency-division multiplexing (OFDM) systems. The cyclic extension, a guardspace preceding OFDM frames, is of decisive importance for this method. It is shown that the redundancy introduced by this cyclic extension allows the estimation to ...

Multi-carrier code division multiplexing (MC-CDM) is one of promising multiplexing techniques for fourth-generation mobile downlink communications systems, where high data rate services should be provided even for high speed-cruising mobiles. For MC-CDM-based packet communication, a frequency scheduling method, which adaptively assigns different sub-carriers to different users, is proposed. Thi...

one of the limitations of orthogonal frequency division multiplexing (ofdm) in many applications is its sensitivity to frequency shifts, errors normally referred to as carrier frequency offset (cfo). although, this small offset is negligible in conventional single carrier communication systems, it is a severe problem in the ofdm systems. because, the carriers in ofdm are inherently closely spac...