Orthogonal code division multiplexing for twisted pair channels
First Claim
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1. A method for developing a signal adapted for transmission over a twisted pair wire comprising the steps of:
- forming a plurality of streams from data of one or more sources, and for each stream j of said plurality of streams performing the steps of;
(a) applying to said stream j a Mj-PAM modulator that converts block of kj bits into symbols having Mj levels, where Mj=2kjthereby creating a Pj modulated signal with a bandwidth related to selected integer value of ki;
(b) splitting said signal Pj into N substreams;
(c) spreading each of said substreams with a different spreading code from an orthogonal code set, each of said different spreading codes being at a common rate Rs; and
combining the spread signals to form said signal adapted for transmission.
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Abstract
A plurality of data signals are separated into parallel bit streams with each parallel stream having a bandwidth characteristic such that the combined cumulative effect of all the individual bandwidths produces a spectral characteristic of the data signals that match the spectral high speed data characteristic of a twisted pair.
67 Citations
12 Claims
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1. A method for developing a signal adapted for transmission over a twisted pair wire comprising the steps of:
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forming a plurality of streams from data of one or more sources, and for each stream j of said plurality of streams performing the steps of;
(a) applying to said stream j a Mj-PAM modulator that converts block of kj bits into symbols having Mj levels, where Mj=2kjthereby creating a Pj modulated signal with a bandwidth related to selected integer value of ki;
(b) splitting said signal Pj into N substreams;
(c) spreading each of said substreams with a different spreading code from an orthogonal code set, each of said different spreading codes being at a common rate Rs; and
combining the spread signals to form said signal adapted for transmission. - View Dependent Claims (4, 6, 11, 12)
summing each Pj plurality of spread signals to form a channel signal; modulating each channel signal with a code;
filtering each modulated channel signal; and
summing the filtered signals.
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12. The method of claim 1, wherein numbers of said modulated signals in the Pj plurality of modulated signals, summed over all values of j, equals number of orthogonal codes in said orthogonal code set.
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2. A method of facilitating high speed data transit over a twisted pair, comprising the steps of:
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demultiplexing an incoming symbol stream having a rate Rs into N parallel symbol streams with rate Rs/N;
applying spreading techniques using orthogonal codes to increase each of the parallel symbol streams to a rate Ns;
summing all the parallel symbol streams and multiplying by a PN code of rate Rs to form a plurality of output pulses; and
shaping said plurality of output pulses so that its cumulative power spectra substantially matches a power transfer function of the twisted pair. - View Dependent Claims (7, 8, 9)
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3. A method of matching a transfer characteristic of a serial stream of data with a power spectrum transfer characteristic of a twisted pair, comprising the steps of:
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enhancing said stream with forward error correction information;
performing serial-to-parallel conversion on the enhanced stream, and modulating the converted signal to obtain pulse amplitude modulated signals in each of parallel branches;
splitting the signal of each parallel branch to form substreams;
spreading the signal of each parallel branch by multiplying each substream of the branch by a different code from a set of orthogonal codes;
summing the spread signals of the parallel branches to create a summed signal;
modifying density of the summed signal by overspreading with a PN cover code to form a white noise spectral distribution of energy; and
filtering results of said modifying to alter spectral distribution of an output signal so as to approximate said transform function for the twisted pair. - View Dependent Claims (5, 10)
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Specification