Data transfer method and system in low voltage networks
This describes data transmission in two-way communication via low-voltage systems that are linked to a higher order telecommunication network.Earlier tone frequency remote control system was there where data was transmitted in one-way communication systems through power lines. This system here enables use of the low-voltage systems of utility companies for two-way communication independent of other carriers. he quality of the signal transmission is strongly polluted by the omnipresent noise, heavily jammed due to a variety of loads and unpredictable effects on signal propagation. For this reason, practical implementation of the high quality transmission through the powerline remains nowadays a difficult issue.
Summary
It uses a higher-order telecommunications networkand data transmission within the low-voltage system takes place at a high-frequency range of up to 30 MHz using band spreading of data signals and a transmitting level below the specified interference or noise voltage limit .The said band-spread data is given a direction coding to specify a logical direction within the low-voltage system using different sequences of a family of pseudo-random numbers to enable multiple-user operation. A correlator placed at an attenuation-dependent distance identifies and regenerates the binary sequences of data. A direction coding using code, time, or frequency multiplexing converts the physical separation which is impossible with data transfer in low-frequency systems.
The proposed method of data transmission at a high frequency range facilitates low-cost bidirectional data transmission in real time via the low-voltage systems of utility companies if buried cables are used.overall transmission capacity of the low-voltage line between connected users channels in ISDN quality with a data rate of 64 kbps can be provided.
further developments
pseudo-random sequences such as Gold sequences is used for user-specific band spreading. the logical direction of the data stream is preset using code multiplexing. The band-spread signals are transmitted in the transmit and receive directions on separate frequency bands or time slots.A CDMA processor for spreading the data using allocated spread sequence and adding the direction code, a modulator for modulating the signals onto a particular carrier frequency, a controllable amplifier to adjust the input level required at the receiving end are used.
for detailed description and drawings, download report:
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also refer this IEEE article:
http://ieeexplore.ieeeXplore/login.jsp?u...ision=-203