1. ABSTRACT New waveform requirements are pushing the limits of traditional modem design techniques. Fortunately, modern Digital-to-Analog Converter (DAC) and Analog-to-Digital Converter (ADC) can achieve sampling rates in the GHz range. These new DACs and ADCs allow designers to directly synthesize channels that have bandwidths of more than 500 MHz+; allowing either wideband or multi-channel m...

The following investigation of post secondary education will proceed via three subdisciplines of modem economic analysis: first, by way of well-known techniques used in the study of public finance (welfare economics); second through models connected with the economic theory of organization; and third through the approach of ʺpublic choiceʺ (the economics of politics). There are important areas ...

Shortage and salinity of irrigation water are two major constraints that influence rapeseed production in arid and semi-arid regions of central and southern Iran. In this study, effects of deficit irrigation with different salinity levels and planting methods (in-furrow and on-ridge) as strategies for coping with water and salinity stresses on yield and yield quality of rapeseed were invest...

The most difficult challenge in upgrading CATV networks for broadband interactive multimedia services lies in the upstream communication path from the customer premises to the headend. This article points out that upstream cable modems are first-of-a-kind modems, which feature intelligent physical layer on top of the basic high speed modem functionalities. After introducing the topic we elabora...

This paper presents the new design of the G3RUH software modem. This is a two level PAM modem that works at range of bit rates from 9600bps to 38400bps and admits different rates at transmission and reception. The major improvement of this new version is the synchronism algorithm and the structure of the reception filter. It provides a better performance of the modem. The software is aimed for ...

This paper presents a new low cost e-mail system for the HF band (3–30 MHz) based on free software and commodity hardware. The core of the system is a 2500 bps OFDM data modem enhanced by turbo codes and a powerful ARQ protocol. The modem has been deeply tested with a Watterson HF channel simulator [?, ], studying the impact of different configurable parameters and comparing its codification st...

1. ABSTRACT Performance requirements for broadband modems continue to push the limits of analog technology. Fortunately, today’s digital–to-analog converters (DACs) are approaching sampling rates in the gigahertz range. These DACs allow broadband modems to implement multichannel solutions completely in the digital domain. To fully utilize the available bandwidth of these DACs, new techniques in...

the category of verbal participation is one of the subjects being studied by the linguists, esp. in semantics. in this vesearch, it has been tried to investigate the old approaches toward this phenomenon in the arabic language and philology. in modem semantics it is called as polysemy. here the polysemy and its technical terms has been scientifically defined. the similarities and differences ha...