Transmission system using transmitter with phase modulator and frequency multiplier

Patent 5903609 Issued on May 11, 1999. Estimated Expiration Date:

June 6, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

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Inventors

Application

No. 659385 filed on 06/06/1996

US Classes:

375/261, Quadrature amplitude modulation332/103, PHASE SHIFT KEYING MODULATOR OR QUADRATURE AMPLITUDE MODULATOR375/298Quadrature amplitude modulation

Examiners

Primary: Chan, Jason
Assistant: Corrielus, Jean B.

Attorney, Agent or Firm

Rubin; Steven S.

Foreign Patent References

53-110355 JP 09/12/1978

International Classes

H04L 23//02
.5/12

Foreign Application Priority Data

1995-06-08 EP

Abstract

A transmission system for transmitting digital symbols by modulation according to a phase constellation includes a transmitter having a phase modulator and a frequency multiplier in cascade for producing a modulated signal having a desired transmission frequency. To prevent degradation of the bit error rate of such signal, the phase constellation at the input of the phase modulator has at least one additional phase state relative to the phase constellation at the output of the frequency multiplier. Advantageously, the number of phase states of the constellation at the input of the phase modulator is N times the number of phase states of the constellation at the output of the frequency multiplier, where N is the frequency multiplication factor.