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US 2004/0165677 A1Published application
Method and system to efficiently modulate data while reducing DC drift
OwnerSheng Shen, Weimin Sun +1inventors
InventorsSheng Shen, Weimin Sun, Bo Zhang
Life of this patent
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Abstract
A method and system of reducing inter symbol interference (ISI) in a multibit symbol modulation scheme. Adjacent symbol pulses are forces to have opposite polarities. Additional phase slots are added to the symbol to modulate any bits lost because amplitude modulation cannot be used. The width of the phase slots is reduced as a result of reduced DC drift and, therefore, ISI.
Claims17
A method comprising:
- defining a modulation symbol to have a first pulse of a first polarity and a second pulse of an opposite polarity, the second pulse adjacent to the first pulse within the symbol;
- expanding a symbol period to accommodate a plurality of additional phase slots one of the first pulse and the second pulse;
- and
- reducing a symbol period by reducing a time for each phase slot on the first and second pulses.
1 more element
A system comprising:
- a processor including a modulator, the modulator to encode data into a symbol comprising a plurality of pulses, such that adjacent pulses of the symbol have an amplitude of opposite polarity;
- a bus coupled to the processor;
- and
- an input output (I/O) device coupled to the bus, the I/O device including a demodulator to recover the data.
1 more element
A method comprising:
- encoding a plurality of data bits as a symbol having a plurality of pulses with adjacent pulses of the symbol having different polarities independent of the data bits encoded;
- and
- transmitting the symbol on a communication channel.
A symbol comprising:
- a first pulse having a polarity and a plurality of phase slots;
- and
- a second pulse having an opposite polarity independent of the data encoded and a plurality of phase slots wherein a minimum size of the phase slots is reduced relative to symbols having adjacent pulse of a same polarity.
A method comprising:
- generating a plurality of single pulse symbols each symbol to encode a plurality of data bits the symbols having a plurality of narrow phase slots including at least one additional narrow phase slot to encode an amplitude Sheng
- forcing adjacent symbols to have opposite polarities independent of data bits encoded.
Dependencies are inferred from the claim text.