Harris Corporation

Harris Stratex Networks, Inc.

Aviat U.s., Inc.

Richard Bourdeau

Tjo San Jao

Am&eacute;vi Kluts&eacute; Ekuhoho

Pierre Ekuhoho

In various embodiments, a first and second complex multiplier may be configured to receive an input signal and provide a baseband I component signal and a baseband Q component signal, respectively. A first and second filter may be configured to filter the baseband I component signal and the baseband Q component signal, respectively. An equalizer may be configured to equalize the filtered baseband I component signal and the filtered baseband Q component signal. A carrier recovery portion may be configured to generate a reference signal based on the equalized filtered baseband I component signal and the equalized filtered baseband Q component signal. A first and second multilevel comparator may be configured to receive the equalized filtered baseband I component signal from the carrier recovery portion and provide an output I and receive the equalized filtered baseband Q component signal and provide an output Q signal for further modulation.

System and method for anticipatory receiver switching based on signal quality estimation

A system and method of switching from a first receiver receiving a constant bit rate signal to a second receiver receiving the constant bit rate signal, where the constant bit rate signal received by the first and second receivers is converted to a first baseband signal and a second baseband signal comprising estimating a signal quality metric of the first baseband signal, comparing the signal quality metric to a predetermined threshold, and switching from the first baseband signal to the second baseband signal if the signal quality metric is greater than the threshold.

A gateless digital circuit and method for generating a second clock with a frequency of N/M of the frequency of a first clock, wherein N and M are integers, N&#x2266;M/2. The gateless digital circuit having a modulo M function, a register and a adder operable connected to generate the second clock, where both N and M are independently selectable.

Apparatus and method for a programmable clock generator

A decision directed frequency detector and method for a quadrature amplitude modulated signal (QAM) demodulator. The demodulator interacts with a voltage controlled oscillator (VCO) that generates a carrier signal to demodulate the QAM signal into a baseband signal. The frequency detector determines the direction of rotation of the baseband signal by sampling the baseband signal relative to predetermined points in the phase plane. For example, if one sample has a negative phase offset with respect to a predetermined point and the next one has a positive phase offset, it detects that the rotation is clockwise, and vice-versa. A control signal is supplied to the VCO and the frequency of the carrier signal is adjusted to stop the rotation of the baseband signal.

Decision-directed carrier frequency detector and method for QAM

A system and method for synchronizing a hub radio and a remote radio by initially changing the frequency of the remote radio by a predetermined frequency offset, and then stepwise changing the frequency as a function of the tolerance of the hub radio to synchronize.

Wideband ranging process for frequency acquisition

A receiver includes a demodulator and a false carrier lock detector circuit for a quadrature amplitude modulated (QAM) signal. The demodulator includes a controllable oscillator and an offset frequency generator for generating an offset frequency for the controllable oscillator to lock to a carrier of the QAM signal. The demodulator is susceptible to false carrier locking responsive to the offset frequency being substantially equal to the symbol rate divided by four or an integer multiple thereof. The receiver further includes the false carrier lock detector circuit including a first detector for detecting consecutive symbols spaced 180.degree. apart, and a second detector for determining whether an intervening sample between the consecutive symbols is outside a predetermined distance from the origin. The first and second detectors cooperate to determine false carrier locking based upon the intervening sample being outside a predetermined distance from the origin.

False carrier lock receiver and associated methods for detection

A device and method for detecting a fault in a cable while the cable is in use. A low frequency analog test signal is added to the signal normally sent across the cable under test. Under normal operating conditions the test signal does not reflect from the load which terminates the cable. Under fault conditions, the test signal is reflected and is detected by an analog test signal detector.

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St-Laurent, Canada

Richard Bourdeau