US 6,389,080 B1 · Random phase shift keying

Abstract

Communication architectures and methods that implement random phase shift keying. A transmitter and a receiver are coupled by way of a communications channel. The transmitter uses a data source and a mapper that produces an amplitude phase keyed (APK) waveform having a plurality of symbol phases. A transmitter multiplier multiplies random phase signals with the APK waveform to produce a random phase keyed output signal. A vector modulator modulates the random phase keyed output signal. A transmitter mixer mixes the random phase keyed output signal with a local oscillator signal from a transmit local oscillator to produce a modulated carrier signal that is transmitted over the communication channel. The receiver has a demodulator including a receiver mixer that receives and mixes the received modulated carrier signal with a local oscillator signal derived from a receive local oscillator to produce an estimate of the random phase keyed signal. The estimated random phase keyed signal is synchronously sampled. A receiver multiplier multiplies a random phase signal with the estimated random phase keyed signal to produce an estimate of the APK waveform. A carrier tracking phase lock loop processes the estimated APK waveform to track the received modulated carrier signal. The present invention makes interception of standard amplitude phase keyed (APK) waveforms virtually impossible.

Claims5

Dependent claims

A communication architecture comprising:

(1) a transmitter comprising:
a data source;
a mapper coupled to the data source that produces an amplitude phase keyed (APK) waveform having a plurality of symbol phases;
a transmitter multiplier for multiplying random phase signals having a random phase sequence with the APK waveform to produce a random phase keyed output signal;
a vector modulator that modulates the random phase keyed output signal to produce a modulated random phase keyed output signal;
and
a transmitter mixer that mixes the modulated random phase keyed output signal with a local oscillator signal output by a transmit local oscillator to produce a modulated carrier signal having a large number of unique phase states for transmission over a communication channel;
(2) a receiver comprising:
a demodulator comprising a receiver mixer that mixes the received modulated carrier signal with a local oscillator signal derived from a receive local oscillator to produce an estimate of the random phase keyed signal;
a receiver multiplier for multiplying a random phase signal with the estimated random phase keyed signal to produce an estimated APK waveform;
and
a carrier tracking phase lock loop coupled between the receiver multiplier and the receive local oscillator for processing the estimated APK waveform to track the received modulated carrier signal.

9 more elements

A communication architecture comprising:

(1) a transmitter comprising:
a data source;
a mapper coupled to the data source that produces an amplitude phase keyed (APK) waveform having a plurality of symbol phases;
a transmitter multiplier for multiplying random phase signals having a random phase sequence with the APK waveform to produce a random phase keyed output signal;
a vector modulator that modulates the random phase keyed output signal to produce a modulated random phase keyed output signal;
and
a transmitter mixer that mixes the modulated random phase keyed output signal with a local oscillator signal output by a transmit local oscillator to produce a modulated carrier signal having a large number of unique phase states for transmission over a communication channel;
(2) a receiver comprising:
a demodulator comprising a receiver mixer that mixes the received modulated carrier signal with a local oscillator signal derived from a receive local oscillator to produce an estimate of the random phase keyed signal;
a receiver multiplier for multiplying a random phase signal with the estimated random phase keyed signal to produce an estimated APK waveform;
and
a carrier tracking phase lock loop for processing the estimated APK waveform to track the received modulated carrier signal that comprises a digital symbol recovery circuit including:
(a) a slicer for making a decision regarding the estimated APK waveform as to which constellation point was received;
(b) a first angle calculator that determines the estimated phase angle of the constellation point estimated by the slicer;
(c) a second angle calculator for determining the real phase angle of the constellation point in the estimated APK waveform;
(d) a comparator for comparing the phase angles derived from the first and second angle calculators to predicts if the estimated phase angle leads or lags the real phase angle;
and
(e) a loop filter for processing the output of the comparator to produce a feedback signal that drives the receive local oscillator.

15 more elements

Dependencies are inferred from the claim text.

Random phase shift keying

Life of this patent

Random phase shift keying

Life of this patent

Abstract

Claims5