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US 2004/0105503 A1Published application
Local communication system and apparatus for use therein
OwnerHosein Mohamadzadeinventor
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OwnerHosein Mohamadzadeinventor
Estimating the term…
An apparatus is disclosed for use as a first station in a network for transmitting and receiving digital data signals. The apparatus comprises a physical layer interface (PLC) for using twisted pair cable in place of optical fibre. The interface comprises a phase shift keying (PSK) encoder (310) and decoder (306) for transmitting and receiving data (TXD/RXD) to and from at least one other station each station including a similar encoder and decoder. The encoder comprises: means for receiving said digital data in the form of an encoded serial data signal together with at least one binary clock signal, the clock signal frequency being a small integer multiple of the data rate; means (402) for synchronising said digital serial data and said binary clock signal such that transitions in the one are aligned with transitions in the other; an encoding logic circuit (404) responsive to said digital serial data signal for selectively outputting one of said binary and the inverse thereof dependent on said serial data signal, so as to generate a PSK encoded binary waveform (Z); and driver means (406-416) for smoothing said encoded binary waveform and imposing the smoothed waveform (Z′) on said conductors in the form of an analogue differential signal pair (TX/nTX). The decoder comprises a differential integrator circuit (504+/504−), to decode such a PSK waveform so as to recover the digital serial data waveform. Various slew rates and decoder time constants are adjustable to suit different data rates. Decoder and encoder can operate synchronised but at different data rates.
A physical layer interface for use in a local communication system for transmitting a digital data of at least 1.41 Mbps gross data rate interface comprising
A physical layer interface as claimed in claim 3 wherein each waveform transition occupies more than 60% of the minimum period between transitions.
An apparatus for use as a first station in a local communication system, the apparatus comprising a phase shift keying (PSK) encoder and decoder for transmitting data to and from at least one other station via electrical conductors, each station including a similar encoder and decoder, the encoder comprising:
A non-coherent PSK decoder comprising an integrator circuit for integrating a received PSK encoded signal and a threshold comparator for converting the integrated signal into a digital data signal, the decoder including means for adapting the decoder to different PSK carrier frequencies by adjusting at least one of the integrator time constant and the comparator threshold.
A non-coherent PSK demodulator comprising an integrator circuit for integrating a received PSK encoded signal and a threshold comparator for converting the integrated signal into a digital data signal, the PSK demodulator comprising a comparator for converting the received PSK signal to a series of binary pulses prior to said integrator circuit, the integrator circuit and threshold comparator thus acting as a pulse width discriminator.
A non-coherent PSK demodulator comprising an integrator circuit for integrating a received PSK encoded signal and a threshold comparator for converting the integrated signal into a digital data signal, the integrator circuit comprising a separate integrator and threshold comparator for positive- and negative-going parts of the received PSK waveform, and a logic circuit or combining the outputs of the comparators to generate a decoded data signal.
Dependencies are inferred from the claim text.