1 This work study the effects of the noise spikes on the digital symbol synchronizers. In these synchronizers, we distinguish two types namely the combinational digital symbol synchronizers and the sequential digital symbol synchronizers. The combinational type has a phase detector without intern memory whereas the sequential type has a phase detector with intern memory. The objective is to stu...

Although there is an increase of performance in DSPs, due to its nature of execution a DSP could not perform high-speed data processing on a continuous data stream. In this paper we discuss the hardware implementation of the amplitude and phase detector and the validation block on a FPGA. Contrary to the software implementation which can only process data stream as high as 1.5 MHz, the hardware...

Synchronisation algorithms for carrier phase recovery and symbol timing in a medium-rate QAM modem are presented. Decision directed (DD) methods that use 1 sample per symbol period are presented. New results are presented to show the eeect of decision errors in the phase detector. The performance of phase and timing estimators is shown when both phase and time oosets are present, and loop conve...

To detect small-scale changes in tissue with optical techniques, small sampling volumes and, therefore, short source–detector separations are required. In this case, reflectance measurements are not adequately described by the diffusion approximation. Previous studies related subdiffusive reflectance to ? or ? , which parameterize the phase function. Recently, it was demonstrated that ? predict...

In this paper we study and present some results on the performances of frequency tracking for Ka-band satellite communications in rain fading channels. The carrier frequency is tracked using a 2 order hyperbolic phase detector based digital-phase locked loop (D-PLL). The hyperbolic D-PLL has the capability of extending the tracking range compared to the other D-PLL and hence can be designed suc...

The nonlinear distortion of a PLL frequency discriminator is addressed using the Volterra Series approach. The analysis, made entirely in the frequency domain, allows distortion calculations for periodic and non-periodic sets of discrete excitation frequencies and random inputs. It also includes, simultaneously, the two major sources of nonlinearity: Phase Detector and VCO.

A PLL circuit includes phase detector for detecting phase error between an input and output signal of the PLL circuit and outputting pump up and pump down signal. A charge pump generates a charge pump signal in response to pump up and pump down signals. A loop filter filters charge pump signal to generate a filtered signal. A boost-up device coupled to loop filter output terminal charges a loop...

The analysis of the stability and numerical simulation of Costas loop circuits for highfrequency signals is a challenging task. The problem lies in the fact that it is necessary to simultaneously observe very fast time scale of the input signals and slow time scale of phase difference between the input signals. To overcome this difficult situation it is possible, following the approach presente...

Spectrally e cient Continuous Phase Modulation for a speci c narrow spectrum requirement mask and a prescribed information bit rate has been designed and analyzed in terms of the minimum Euclidean distance and simulated symbol error probability for the AWGN channel. The performance of a low complexity sub-optimum detector based on an approximate lter bank and a reduced state Viterbi decoder for...

In this letter, we propose a polarity decision carrier recovery algorithm that is useful for carrier acquisition in high order QAM. The PD (Phase Detector) output and its variance characteristic are mathematically derived and the simulation results are presented. The proposed algorithm shows enhanced acquisition performance especially for large frequency offset. key words: carrier recovery, QAM...