Lucent Technologies Inc.

Agere Systems Inc.

Jack P Glas

Vladimir Ivanov Prodanov

Hongmo Wang

Maurice J Tarsia

The present invention is directed toward a radio, and method for receiving radio frequency signals. The radio comprises an input signal at a first intermediate frequency, an intermediate sampling architecture, a quantizer and a baseband converter. The intermediate frequency sampling architecture comprises receiving the input signal, passing the first intermediate frequency signal through a first filter characterized by steep selectivity and narrow bandpass, converting the filtered signal to a second intermediate frequency and passing the second intermediate frequency signal through a second filter having a bandpass characteristic, but without the steep selectivity characterizing the first filter. The radio further comprises a third filter following the baseband conversion which filters out adjacent channel harmonics to obtain a wanted data signal.

System and method for an IF-sampling transceiver

The present invention is directed towards a data detector for deriving a data signal from an incoming radio frequency input. The data detector comprises a delay logic which receives an unfiltered signal in quadrature and in-phase components, and applies a delay to each of the in-phase and quadrature phase components of the unfiltered input signal. The detector further comprises a first multiplication logic that multiplies the delayed in-phase component of the unfiltered signal by the quadrature phase component of the unfiltered signal to obtain a first result, and a second multiplication logic that multiplies the delayed quadrature phase component of the unfiltered signal by the in-phase component of the unfiltered signal to obtain a second result. Finally, an adder adds the first result with the second result to generate a data signal. In alternative embodiments a post detection correction algorithm may be added to improve performance.

System and method for differential data detection

The modulator includes an oscillator generating signals, each having a different phase, and a selector receiving digital data. When the digital data received by the selector changes logic state, the selector supplies a first and second plurality of signals generated by the oscillator to first and second non-linear amplifiers, respectively. An adder then adds the output of each amplifier to generate a radio frequency output.

Method and apparatus for modulating digital data

In a communications terminal that has an image reject mixing arrangement, a compensation system provides compensation for phase and amplitude imbalances, which are caused by a demodulating local oscillator employed in the communications terminal. The image reject mixing arrangement comprises a radio-frequency (RF) mixing stage including an in-phase and a quadrature phase branch, which is configured to receive a radio frequency signal and down convert the radio frequency signal to in-phase and quadrature phase intermediate frequency (IF) signals. It also includes a phase splitter unit coupled to the radio-frequency (RF) mixing stage and configured to provide an in-phase local oscillator signal and a quadrature phase local oscillator signal to the RF mixing stage. The phase splitter causes an amplitude imbalance signal &Dgr; and a phase imbalance signal &phgr; to be generated in the in-phase and quadrature phase branch of the RF mixing stage. A phase splitter compensation unit is coupled to the RF mixing stage and is configured to multiply the in-phase and quadrature phase signals provided by the RF mixing stage by a predetermined compensation factor. An intermediate frequency (IF) mixing stage is coupled to the radio-frequency mixing stage via the phase splitter compensation unit. The IF mixing stage is configured to convert the intermediate signals received from the RF mixing stage to base band frequency region.

Digital I/Q imbalance compensation

A circuit for receiving an input signal having a phase component and an amplitude component which carry information, and for producing an output driver signal containing the phase and amplitude component information for driving a non-linear amplifier for generating linear amplification. The circuit includes a voltage controlled oscillator for receiving the phase component and for outputting a phase modulated carrier signal having a duty cycle and a constant amplitude. A driver stage made from a plurality of invertors, each having a pair of MOSFET transistors, receives the carrier signal at the gate terminals of the transistors. The amplitude component is used to drive the invertors by applying the amplitude component to the backgate terminals of at least some of the transistors in the invertors to pulse width modulate the carrier signal. The resulting output signal containing both phase component information and amplitude component information can then be used to drive a non-linear Class S amplifier to generate linear amplification while achieving high efficiency.

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Basking Ridge, NJ, United States of America

Jack P Glas