Parkervision, Inc.

Unisys Corporation

Robert T Short

Michael J Bultman

Richard C Looke

Robert W Cook

Charley D Moses, Jr

David F Sorrells

Martin R Johnson

Jonathan S Jensen

Jamison L Young

Gregory S Rawlins

Michael W Rawlins

Francis James Smith

Craig K Rushforth

Zhenhua Xie

David F Sorrels

Danny E Stoneking

Charly D Moses

Methods, systems, and apparatuses for down-converting an electromagnetic (EM) signal by aliasing the EM signal, and applications thereof are described herein. Reducing or eliminating DC offset voltages and re-radiation generated when down-converting an electromagnetic (EM) signal is also described herein. Down-converting a signal and improving receiver dynamic range is also described herein.

Down-conversion of an electromagnetic signal with feedback control

A universal frequency translation module (UFT) frequency translates an electromagnetic (EM) input signal by sampling the EM input signal according to a periodic control signal (also called an aliasing signal). By controlling the relative sampling time, the UFT module implements a relative phase shift during frequency translation. In other words, a relative phase shift can be introduced in the output signal by sampling the input signal at one point in time relative to another point in time. As such, the UFT module can be configured as an integrated frequency translator and phase-shifter. This includes the UFT module as an integrated down-converter and phase shifter, and the UFT module as an integrated up-converter and phase shifter. Applications of universal frequency translation and phase shifting include phased array antennas that utilize integrated frequency translation and phase shifting technology to steer the one or more main beams of the phased array antenna.

Phased array antenna applications on universal frequency translation

DC offset, re-radiation, and I/Q solutions using universal frequency translation technology

Phased array antenna applications of universal frequency translation

A method and system for converting an optical signal to electrical information signals, including demodulated baseband information signals and modulated baseband signals at multiple harmonics. In an embodiment, the optical information signal is amplitude modulated with information. The method converts an optical signal to electrical charge, accumulates the electrical charge, and periodically transfers the accumulated electrical charge to a storage device, whereby the periodically transferred electrical charge forms the electrical signals. An exemplary system includes an optical transducer and a universal frequency translator coupled to an output of the optical transducer. The optical transducer receives an optical signal and converts the optical signal to electrical charge. The universal frequency translator periodically transfers energy from the electrical charge and forms the electrical signals from the transferred energy. In an embodiment, the present invention converts an I and Q optical signal to electrical signals. In an embodiment, the present invention converts an optical signal to an RF electrical signal using relatively few components, while preserving information content.

Optical down-converter using universal frequency translation technology

Phase shifting applications of universal frequency translation

Coherent detection of a received EM signal using universal frequency translation (UFT) is described herein. The received EM signal is sampled according to a sub-harmonic LO signal, where the LO signal is in frequency and phase coherence with the received EM signal. The coherent receiver includes a down-converter/demodulator and a synthesizer/loop filter that are both implemented using UFT technology. The down-converter/demodulator samples the EM input signal using a UFT module according to the coherent sub-harmonic LO signal that is generated by the synthesizer/loop filter. The synthesizer/loop filter generates the coherent LO signal using a phase detector, a loop filter, and an up-converter. The phase detector and up-converter are implemented using UFT modules.

Carrier and clock recovery using universal frequency translation

A composite signal is formed by simultaneously transmitting multiple asynchronous data bit sequences, that are coded with respective spreading codes, in a single channel; and a circuit is provided which decodes any bit b(x) in that composite signal. This circuit includes a set of filters which are matched to all of the spreading codes and which obtain (a) a matched filter output signal y(x) for the x-th data bit b(x) and (b) matched filter output signals y(x+1) thru y(x+k-1) for the k-1 data bits that immediately follow data bit b(x); K is the number of bit sequences in the composite signal. An arithmetic unit combines the matched filter output signals via the expression: ##EQU1## where H(x,x.+-.i) is the cross correlation of the spreading codes for data bits b(x) and b(x.+-.i) over the time period that those data bits overlap (and thus add) in the composite signal, and ESTb(x-i) is an estimate of data bit b(x-i) which precedes bit b(x). An output unit decodes the data bit b(x) as a '1' if the above expression is positive, and as a '0' if the above expression is negative. In one embodiment, ESTb(x-i) is the SIGN of a matched filter output y(x-i) for data bit b(x-i). In another embodiment, ESTb(x-i) is the result from the output unit which decoded data bit b(x-i).

Decoder for added asynchronous bit sequences

Data bits are decoded from a composite signal that is formed by coding multiple bit sequences with respective spreading codes, and transmitting the coded bit sequences simultaneously and asynchronously over a single channel in which the bit sequences are added. This decoding involves a metric in combination with a repetitive decision process which is only linearly dependent on the number of bit sequences in the composite signal.

Method and apparatus for decoding multiple bit sequences that are

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Salt Lake City, UT, United States of America

Robert T Short