L-3 Communications Corporation

L3 Technologies, Inc.

William K McIntire

Larry S Thomson

David H Robbins

Osama Sami Haddadin

James J Boesch

June Y Sun

Roy E Prymek

Samuel Charles Kingston

Johnny M Harris

David G Landon

Janez Jeraj

Michael Rice

Thomas R Giallorenzi

Ryan W Hinton

L Andrew Gibson

Dale D Fonnesbeck

Anthony D Smith

John James Carver, Ii

David J Moore

One embodiment illustrated herein includes a system for simulating communications in an environment. The system includes a postulated physical environment model, having modeled terrain and continuous changes over time. A channel parameter calculator is coupled to the postulated physical environment model, and configured to obtain samples from the postulated physical environment model, each sample comprising information about modeled terrain at a given time. The channel parameter calculator is further configured to, from the obtained samples, generate communication channel parameters, over time. A channel simulator is coupled to the channel parameter calculator. The channel simulator is configured to be coupled to signal source and to, using the communication channel parameters, apply the communication channel parameters to a communication signal from the signal source to simulate transmission of data through a simulated channel over time.

Real-time calculator for high precision channel simulator effects

Embodiments are directed to systems, apparatuses and methods for providing self-consistent outphasing signal separation. In one scenario, such an apparatus includes the following: a receiver configured to receive a variable-envelope signal and an outphasing separator including a digital electronic component configured to split the received variable-envelope signal into first and second constant-envelope signals. Splitting the received variable-envelope signal includes implementing various trigonometric or other functions using a consistent phase. The apparatus further includes a first analog component chain that includes various analog electrical components configured to receive and process the first constant-envelope signal, as well as a second analog component chain that includes various analog electrical components configured to receive and process the second constant-envelope signal. The apparatus also includes an analog combiner configured to combine the first and second constant-envelope signals for transmission to other entities or systems.

Self-consistent outphasing signal separation

Embodiments are directed to an apparatus, method and system for relative or absolute equalization of two or more channels. The apparatus includes a receiver that receives a variable-envelope signal, a self-consistent outphasing separator that splits the received variable-envelope signal into constant-envelope signals, and linear pre-equalizers that equalize the constant-envelope signals relative to each other or to some target. The apparatus also includes an analog combiner that combines the constant-envelope signals, and a feedback loop with a processor that receives the combined constant-envelope signals as inputs, analyzes the combined constant-envelope signals to identify pre-equalization inputs that, when applied to the linear pre-equalizers, will equalize the constant-envelope signals, and provide the identified pre-equalization inputs to the linear pre-equalizers, so that the combined constant-envelope signals are equalized relative to each other or to some target. Adaptive algorithms use a dedicated calibration signal, regularly transmitted (data) signal or combination of the two.

Linear equalizers for outphasing amplification

A digital transmitter channel optimization device can be employed within or in conjunction with a transmitter to perform a number of techniques in the digital domain to account for distortion introduced in the transmitter. The optimization device can be configured to perform such techniques on an arbitrary signal to thereby allow the optimization device to be used with virtually any transmitter. The optimization device may be particularly beneficial in wideband systems where accounting for distortion can be difficult to accomplish using existing techniques.

Digital Transmitter channel optimization device

Adaptive filtering is used to substantially cancel distortion in radio frequency (RF) signals. Such adaptive filtering can be used in an RF transmitting module to pre-compensate an RF signal with compensation (inverse) distortion to cancel inherent transmission path distortion from the RF signal. Adaptive filtering can also be used in a multi-carrier RF receiving module to cancel from a given carrier signal distortion due to cross talk from adjacent carrier signals. Adaptive filtering in an RF transceiver can be used to cancel from a received RF signal distortion arising from leakage of a transmit signal into the receive path.

Adaptive filtering for canceling distortion in radio frequency signals

The peak-to-average power ratio of an input signal can be reduced prior to amplification. This reduction in the peak-to-average power ratio can be accomplished without adding significant intermodulation distortion to the input signal. The resulting input signal can therefore have a peak-to-average power ratio that does not exceed the output backoff of the amplifier thereby preventing the amplifier from being operated in saturation and, as a result, minimizing the intermodulation distortion added by the amplifier. The peak-to-average power ratio of an input signal can be reduced using two stages of signal clipping. By employing two stages, the intermodulation distortion introduced to the input signal as it passes through the stages is minimized. Also, because this two-stage approach does not attempt to account for intermodulation distortion introduced by the downstream amplifier, it can be implemented without any prior knowledge of the amplifier's transfer function or any output monitoring scheme.

Peak-to-peak average power ratio reduction and intermodulation distortion pre-suppression using open-loop signal processing

Adaptive filtering is used to substantially cancel distortion in radio frequency (RF) signals. Such adaptive filtering can be used in an RF transmitting device to pre-compensate an RF signal with compensation (inverse) distortion to cancel inherent transmission path distortion from the RF signal. Adaptive filtering can also be used in a multi-carrier RF receiving device to cancel from a given carrier signal distortion due to cross talk from adjacent carrier signals. Adaptive filtering in an RF transceiver can be used to cancel from a received RF signal distortion arising from leakage of a transmit signal into the receive path.

Adaptive filtering for canceling leaked transmit signal distortion from a received RF signal in an RF transceiver

Techniques for modulation and demodulation using near-Nyquist sampling operate using substantially band-limited signal. In modulating, the substantially band-limited signal is formed by filtering modulated symbol date to produce a complex sample stream having a bandwidth of less than the twice the associated symbol transmission rate and with a sample rate of less than twice the symbol rate. In demodulating, a substantially band-limited signal having a bandwidth of less than twice the associated symbol transmission rate is sampled at a sample rate of less than twice the symbol rate of the modulation.

Modulation and demodulation of band-limited signals using near-Nyquist sampling

A method for timing a full duplex pulsed wireless communication system between first and second transceivers is disclosed. At least one of the transceivers is mobile. A propagation time between the first and second transceivers is calculated. A pulse period of the first transceiver is set to be twice the propagation time divided by an integer. The second transceiver's pulse period is set to be equal to the pulse period of the first transceiver to enable the first and second transceivers to transmit and receive pulses with a substantially reduced risk of a collision between pulses transmitted from the first and second transceivers.

Method for timing a pulsed communication system

A method for asynchronous transmission of communication data between periodically blanked terminals separated by an unknown distance is disclosed. A bursted signal is transmitted from a first terminal with a burst time tand a burst cycle period T. The bursted signal is received at a second terminal. A bursted response signal is transmitted from the second terminal to the first terminal. The bursted response signal has a burst cycle period of T/2 and includes a pair of response bursts, with each burst in the pair having a burst time t&#x2266;T/2&#x2212;t. Each burst in the pair of response bursts carries an identical data payload. At least one of the response bursts is received at the first terminal.

Method for asynchronous transmission of communication data between periodically blanked terminals

A method for transmitting low data rate symbols from a burst radar transceiver is disclosed. The method includes dividing a symbol having a symbol period into a plurality of symbol sections. Each symbol section has a symbol section interval that is less than or equal to a burst interval of the radar transceiver. At least two symbol sections can be transmitted with the burst radar transceiver. Symbol energy can be accumulated from the at least two symbol sections at the communications terminal. Information in the received symbol sections can be identified based on characteristics of the accumulated symbol energy.

System and method for communicating low data rate information with a radar system

A method is disclosed for transmitting low data rate symbols from a communications terminal to a burst radar transceiver. A plurality of bursts can be emitted from a burst radar transceiver, each burst having a burst interval and separated by an inter-burst interval. A symbol can be transmitted from the communications terminal to the burst radar transceiver. The symbol has a symbol period that is substantially longer than a radar transceiver burst period comprising the burst interval and the inter-burst interval. Symbol energy can be accumulated during inter-burst intervals at the burst radar transceiver over a plurality of burst periods for approximately the symbol period.

A method for transmitting bursts of data from a communications terminal to a mobile radar transceiver having inter-burst periods is disclosed. The method includes determining a propagation time between the communications terminal and mobile radar transceiver. A length of inter-burst periods of the mobile radar transceiver having an inter-burst timing can be determined. Bursts of data having a communication burst period that is less than the inter-burst period can be formed. The bursts of data from the communications terminal can be transmitted at a transmission time based on the inter-burst timing and the propagation time to enable each burst of data to be received by the mobile radar transceiver during one of the inter-burst periods.

Growing community of inventors

Sandy, UT, United States of America

William K McIntire