Northrop Grumman Systems Corporation

Trw Limited

Other

Trw Docket No.

Donald R Martin

Mark Kintis

Vincent C Moretti

William Marvin Skones

Andrew Donovan Smith

Shimen K Claxton

Craig R Talbott

Bert K Oyama

Scott Adam Stephens

John E Ohlson

Terrence R Smigla

Barry Ross Allen

Ronald P Smith

David Joseph Brunone

Kenneth Weber

Robert R Harnden

Eric L Upton

Jeffrey Mark Hinrichs

Donald L Lochhead

Mark V Keller

Brian J Rosenkoetter

Kai E Johnson

A multi-carrier receiver system and method for receiving a transmission frequency multi-carrier signal include a feedforward cancellation loop. A frequency conversion circuit generates an intermediate frequency (IF) multi-carrier signal based on the transmission frequency multi-carrier signal. The feedforward cancellation loop generates an amplitude corrected multi-carrier signal based on the IF multi-carrier signal such that the amplitude corrected multi-carrier signal has a reduced dynamic range with respect to the IF multi-carrier signal. A primary A/D converter having a significantly lower dynamic range requirements can therefore generate a digital multi-carrier signal based on the amplitude corrected multi-carrier signal. The feedforward cancellation loop therefore enables the primary A/D converter to process multi-carrier signals without the need for large dynamic range requirements.

Feedforward amplitude cancellation topology for multi-carrier applications

An apparatus for converting a digital input signal to an analog signal for transmission. The input signal can include more than one carrier signal. A plurality of delta-sigma modulation loop circuits are connected in an increasing order of operating frequency so as to reduce a word length of the input signal. A tuning circuit adjusts the signal frequency to a transmitting frequency for conversion to analog by a digital-to-analog converter. A first loop circuit is implemented using CMOS gates, and a second loop circuit and the tuning circuit are implemented using indium phosphide gates. The apparatus allows a high-resolution, wide-band RF multiple-carrier signal to be re-quantized to a lower-resolution signal while an acceptable signal-to-noise ratio is maintained.

Apparatus and methods for digital-to-analog conversion

A receiver ( ) for a wireless telecommunications system that provides relatively wideband signal processing of received signals without increased signal distortion so that multiple received signals can be simultaneously processed. The receiver ( ) includes a specialized LNA ( ), frequency down-converter ( ) and ADC ( ) to perform the wideband signal processing while maintaining receiver performance. The frequency down-converter ( ) employs a suitable mixer ( ), BPA ( ), attenuator ( ), and transformer ( ) that are tuned to provide the desired frequency down-conversion and amplitude control over the desired wideband. The down-converter devices are selected depending on the particular performance criteria of the ADC ( ). A specialized digital channelizer ( ) is included in the receiver ( ) that receives the digital signal from the ADC ( ), and separates the signals into the multiple channels. In one embodiment, the frequency down-conversion is performed in a single down-conversion process, and the ADC ( ) employs delta-sigma processing to provide digital conversion over the complete frequency band. In an alternate embodiment, the frequency down-conversion is performed in a double down-conversion process so that a less complex ADC ( ) can be used.

Wireless telecommunications multi-carrier receiver architecture

Receiver including frequency down-converter and analog-to-digital converter for a wireless telecommunication system

A receiver ( ) for a wireless telecommunications system that provides relatively wideband signal processing of received signals without increased signal distortion so that multiple received signals can be simultaneously processed. The receiver ( ) includes a specialized LNA ( ), frequency down-converter ( ) and ADC ( ) to perform the wideband signal processing while maintaining receiver performance. A specialized digital channelizer ( ) is included in the receiver ( ) that receives the digital signal from the ADC ( ), and separates the signals into the multiple channels. In one embodiment, the frequency down-conversion is performed in a single down-conversion process, and the ADC ( ) employs delta-sigma processing to provide digital conversion over the complete frequency band.

Multi-carrier receiver including an analog-to-digital converter for a wireless telecommunication system

Architecture for multi-carrier receiver

Receiver including low noise amplifier and frequency down-converter for a wireless telecommunication system

A communications waveform format is provided for a satellite-based telecommunications system. The waveform format includes forward and return link waveforms between the satellite, earth stations and terminals. The forward and return links use orthogonal direct-sequence code division multiple access (ODS-CDMA) to minimize interference between users. The forward and return link spectrum may be divided into channels, the frequencies and spacing of which are adjustable to compensate for Doppler effects, thereby maintaining synchronization. The spectrum of the terminal links may be divided into multiple subbands (e.g., 38), each of which may support multiple (e.g., 80) ODS-CDM channels. The forward and return links support traffic channels (TCH), associated signaling channels (ASC), broadcast control channels (BCC), forward signaling channels (FSC) having paging slots (PAS) and channel allocation slots (CAS), call establishment channels (CEC), and loop signaling channels (LSC), a measurement reporting channel (MRC), and a return access channel (RAC). The RAC carries nonsynchronous spread spectrum pseudo-noise (PN) signal access bursts which are used by terminals to initially access the communications system.

Orthogonal code division multiple access waveform format for use in satellite based cellular telecommunications

A power control system for a multi-carrier base station transmitter is capable of controlling power levels of individual RF carriers. The power control system has a multi-channel amplification system for converting a plurality of analog input signals into a plurality of amplified carrier signals. The amplification system also generates a plurality of reference signals corresponding to the amplified carrier signals. Furthermore, the amplification system generates a multi-carrier signal, where the multi-carrier signal includes a summation of the amplified carrier signals. A correlating power detection system is connected to the amplification system, where the correlating power detection system generates total power control signals based on the reference signals and the multi-carrier signal. The power control system also has an adjustment module connected to the amplification system and the power detection system, where the adjustment module controls amplification of the carrier signals based on the total power control signals. Sampling the amplified signals to obtain reference signals, and using these reference signals for control purposes allows greater power control than available under conventional approaches.

Analog power control system for a multi-carrier transmitter

Multi-carrier receiver for a wireless telecommunication system

A power control system for a multi-carrier base station transmitter is capable of controlling power levels of individual RF carriers. The power control system has a multi-channel conversion system for generating a plurality of analog reference signals corresponding to a plurality of digital input signals. The multi-channel conversion system also generates an analog multi-carrier signal and samples the multi-carrier signal. The multi-carrier signal represents a summed amplification of the digital input signals. A correlating power detection system is connected to the multi-channel conversion system and generates digital total power control signals based on the analog reference signals and the analog sampled multi-carrier signal. A feedback conversion module is connected to the multi-channel conversion system and the correlating power detection system and individually controls amplification of the digital input signals based on the total power control signals.

Digital power control system for a multi-carrier transmitter

A communications waveform format is provided for a satellite-based telecommunications system. The waveform format includes forward and return link waveforms between the satellite, earth stations and terminals. The forward and return links use orthogonal direct-sequence code division multiple access (ODS-CDMA) to minimize interference between users. The forward and return link spectrum may be divided into channels, the frequencies and spacing of which are adjustable to compensate for Doppler effects, thereby maintaining synchronization. The spectrum of the terminal links may be divided into multiple subbands (e.g., 38), each of which may support multiple (e.g., 80) ODS-CDMA channels. The forward and return links support traffic channels (TCH), associated signaling channels (ASC), broadcast control channels (BCC), forward signaling channels (FSC) having paging slots (PAS) and channel allocation slots (CAS), call establishment channels (CEC), and loop signaling channels (LSC), a measurement reporting channel (MRC), and a return access channel (RAC). The RAC carries nonsynchronous spread spectrum pseudo-noise (PN) signal access bursts which are used by terminals to initially access the communications system.

A communications waveform format is provided for a satellite-based telecommunications system. The waveform format includes forward and return link waveforms between the satellite, earth stations and terminals. The forward and return links use orthogonal direct-sequence code division multiple access (ODS-CDMA) to minimize interference between users. The forward and return link spectrum may be divided into channels, the frequencies and spacing of which are adjustable to compensate for Doppler effects, thereby maintaining synchronization. The spectrum of the terminal links may be divided into multiple subbands (e.g., 38), each of which may support multiple (e.g., 80) ODS-CDMA channels. The forward and return links support traffic channels (TCH), associated signaling channels (ASC), broadcast control channels (BCC), forward signaling channels (FST) having paging slots (PAS) and channel allocation slots (CAS), call establishment channels (CEC), and loop signaling channels (LSC), a measurement reporting channel (MRC), and a return access channel (RAC). The RAC carries nonsynchronous spread spectrum pseudo-noise (PN) signal access bursts which are used by terminals to initially access the communications system.

A communication system (,) implemented to be specifically matched to the time and spatially dependent statistics of a transmission channel (,). The communication system (,) is used for broadcasting over the channel (,) to users in a coverage region (,). The communication system (,) includes a transmitter (,) having an error correction encoder (,) and a weighted interleaver (,). The error correction encoder (,) includes a first input to receive data bits and a first output. The error correction encoder (,) expands each data bit received at said input by an encoder rate. The weighted interleaver (,) includes a second input to receive the expanded data bits and a second output. The weighted interleaver (,) has a non-uniform delay distribution between a minimum delay and a maximum delay to interleave the expanded data bits by the non-uniform delay distribution. The communication system (,) also employs a weighted link margin matched to the time and spatially dependent statistics of the transmission channel.

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Redondo Beach, CA, United States of America

Donald R Martin