Prefilter bandwidth effects in data symbol phase synchronizers of open loop

This work studies the effects of the prefilter bandwidth on the open loop symbol synchronizers. We consider three different prefilter bandwidth, namely, B1=¥ ( infinite), B2=2.tx and B3=1.tx, where tx is the transmission rate. We consider also four open loop symbol synchronizers, namely, the tank (tank), the SAW (SAW), the monostable (mon), and the astable (ast). The objective is to study the prefilter bandwidth with the four open loop symbol synchronizers and to evaluate their output jitter UIRMS (Unit Interval Root Mean Square) versus input SNR (Signal to Noise Ratio)

Prefilter bandwidth effects in sequential symbol synchronizers based on clock sampling by positive transitions

This work studies the effects of the prefilter bandwidth in the sequential symbol synchronizers based on clock sampling by positive transitions. The prefilter bandwidth B is switched between three values, namely B1=∞, B2=2. tx and B3=1. tx, where tx is the bit rate. The synchronizer has two variants, one discrete and other continuous. Each variant has two versions, one manual and other automatic. The objective is to study the prefilter bandwidth with the four synchronizers and to evaluate their output jitter UIRMS (Unit Interval Root Mean Square) versus input SNR (Signal to Noise Ratio)

Effects of the previous pulse shift and filter on the symbol synchronizer PLL

We will study the effects of the shift of the previous pulse temporal position (between P1 and P2) on the symbol synchronizers jitter behavior. Each pulse temporal position (P1 and P2), with the same previous filter, forms a group with four different carrier PLL (Phase Lock Loop) namely the analog, hybrid, combinational and sequential. The main objective is to study the synchronizers output jitter UIRMS (Unit Interval Root Mean Squared) as function of the input SNR (Signal to Noise Ratio)

Sequential symbol synchronizers based on pulse comparison operating by positive transitions at quarter rate

This work presents the sequential symbol synchronizer based on pulse comparison by positive transitions at quarter rate (txp/4). Their performance is compared with a reference synchronizer by both transitions at the rate (tx). For the reference and proposed synchronizer we consider two versions which are the manual (m) and the automatic (a). The objective is to study the four synchronizers and evaluate their output jitter UIRMS (Unit Interval Root Mean Square) versus input SNR (Signal Noise Ratio)

Sequential symbol synchronizers based on clock sampling by positive transitions

This work presents a sequential symbol synchronizer, that was discovered by us, and its functioning principle is based on the clock sampling by the input positive data transitions. This synchronizer has two topologies, namely the discrete and the continuous. Also, each topology has two versions which are the manual and the automatic. These synchronizers are very interesting, because the previous adjust of the manual version isn’t critical. The objective is to study the four synchronizers and to evaluate their output jitter UIRMS (Unit Interval Root Mean Square) versus input SNR (Signal to Noise Ratio)

Sequential symbol synchronizers based on pulse comparation at Half Rate

This work presents a synchronizer based on pulse comparation, between variable and fixed pulses. We consider four synchronizers, divided in two variants, one variant operate at the rate and the other at half rate. Each synchronizer variant has two versions which are the manual and the automatic. The objective is to study the synchronizers and evaluate the output jitter UIRMS (Unit Interval Root Mean Square) versus the input SNR (Signal Noise Ratio)

Deterministic and random phase synchronizers

This work study two groups of synchronizers, namely the Deterministic Phase Synchronizer and the Random Phase Synchronizer. The difference between them is only inside of the phase comparator. In the first group, the VCO (Voltage Controlled Oscillator) synchronizes with the input deterministic phase of an expected periodic transition. In the second group the VCO synchronizes with the input random phase of an unexpected no periodic transition. Each group is studied under four topologies (analog, hybrid, combinational and sequential). The objective is to evaluate the two synchronizers groups with the four topologies and to observe their jitter behaviors with the noise

Performance Evaluation of Laboratory Wi-Fi ieee 802.11g wpa Point-to-Point Links Using TCP, UDP and FTP

AbstractWireless communications, e.g. Wi-Fi, have been increasingly important in the context of networked and virtual organizations and enterprise information systems. Performance is an issue of crucial importance, resulting in more reliable and efficient communications, therefore improving enterprise information system yield. Security is equally important. Laboratory measurements are made about several performance aspects of Wi-Fi IEEE 802.11g WPA point-to-point links. A contribution is given to performance evaluation of this technology under WPA encryption, using available equipments (DAP-1522 access points from D-Link and WPC600N adapters from Linksys). New detailed results are presented and discussed, namely at OSI levels 4 and 7, from TCP, UDP and FTP experiments, permitting measurements of TCP throughput, jitter, percentage datagram loss and FTP transfer rate. Comparisons are made to corresponding results obtained for open links. Conclusions are drawn about the comparative performance of the links