Hughes Electronics Corporation

Tom Jackson

Henry Eck

Mohammad Soleimani

Dave Roos

Jack Lundstedt

D Ray Lowe

Royce Hernandez

Guy Montgomery

Ray Lowe

Eryx Malcolm

Circuitry for modulating the frequency of a carrier signal with data signals for high frequency radio transmission, which includes a MSK generator for generating a series of in-phase (I) signals and an associated series of quadrature (Q) signals corresponding to the data signals to be transmitted. A first shift register receives binary input from the I signals generated with the MSK generator, the binary input being indicative of the sign orientation of the generated I signals from the MSK generator. A second shift register receives binary input from the Q signals generated with the MSK generator, with the binary input being indicative of the sign orientation of the generated Q signals from the MSK generator. A first finite impulse response (FIR) filter is provided for summing a series of delayed binary input received from the I signals at the first shift register to generate filtered I signals, and likewise a second FIR filter is provided for summing a series of delayed binary input received from the Q signals to generate filtered Q signals. A local oscillator (LO) generates the carrier signal, and an I/Q modulator is used for modulating the phase shift of the LO signal according to the filtered I signals and the filtered Q signals from the first and second FIR filters respectively.

Efficient implementation for systems using CEOQPSK

A method and system for using a low-cost, fixed output power radio in a multi-carrier communication system is disclosed herein. This system measures the output power of the multiple channel units within the system, obtains the current output power of the system, calculates a composite power and an expected power, compares the expected power and the current output power to calculate a gain adjustment value, and adjusting the output power of the system via the amplifier. The method for adjusting the power can also allow at least one of the carriers in the multi-carrier system to operate in a burst mode, and at least one of the remaining carriers to operate in a continuous mode during power measurement and gain adjustment steps.

Operation of low-cost, fixed output power radio in fixed gain mode

A method and device for canceling frequency offsets in received modulated signals. The frequency offset cancellation device includes a downconverter module, a channel unit and a control module. The downconverter module shifts received signals to a lower frequency. The channel unit searches the shifted received signals and demodulates them, and the control module adjusts the downconverter in accordance with frequency offset information generated by the channel unit, thereby continuously cancelling out any frequency offsets that may have occurred during frequency shifting.

Method and device for canceling frequency offsets

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Frederick, MD, United States of America

Tom Jackson