Delco Electronics Corporation

Delphi Technologies, Inc.

Aptiv Technologies Limited

Jeffrey J Marrah

Gregory J Manlove

Richard A Kennedy

Linh Ngoc Pham

Harry Diamond

Fred Jay Anderson

Raed S Shatara

Mark A Kady

Michael John Easterwood

Seyed R Zarabadi

Glenn A Walker

Eric A Dibiaso

Myron Glen Padgett

Ronald W Dale

Richard Sidney Stroud

Douglas A Cramer

Marvin G Stang

Rohail Andrew Pervez

Douglas E White

Matthew C Reprogle

Matthew James Yarosz

Thomas Joseph Kennelly

Shuping Zhang

High priority data and low priority digital data are transmitted as primary and secondary data in hierarchically modulated, orthogonal frequency division multiplexing (OFDM) from an earth-orbiting satellite. To enable the transmitter amplifier to be operated with less back-off from saturation without clipping, the low priority OFDM symbols have fewer samples than the high priority OFDM symbols, and the high priority samples on which the low priority samples are superimposed are selected according to a first deterministic rule using sample power comparisons of the high priority samples to concentrate the low priority samples on those high priority samples having lower (optimally, the lowest) sample power. The low priority samples are distributed on the selected high priority samples according to a second deterministic rule relating the original low priority sample order to the original high priority sample order.

Hierarchically modulated OFDM communication from a satellite-based transmitter with reduced secondary data loss from clipping

A system and method of a stereo receiving system, including a plurality of antennas, a receiving device, a plurality of summing devices, a phase lock loop device, a controllable phase shifter device, and a gain-control device. The plurality of antennas receive RF signals having a common frequency but potentially different phases. The receiving device is in electrical communication with the plurality of antennas. The plurality of summing devices are in electrical communication between at least one of the plurality of antennas and the receiving device. The phase lock loop device is in electrical communication with the receiving device. The gain-control device is in electrical communication between the plurality of antennas and the receiving device, wherein the gain-control device controls a signal-to-noise ratio of the RF signals aligned from the plurality of antennas.

System and method of a stereo receiving system

An SDARS receiver for use with at least two antennae, each of which receives bitstreams from a first satellite, bitstreams from a second satellite, and bitstreams from a terrestrial repeater, including demodulators configured to switch between demodulating bitstreams from the satellites and to switch between demodulating bitstreams from the terrestrial repeater, and a processor coupled to the demodulators, the processor being configured to switch the demodulators according to a variety of algorithms.

Satellite receiver system

An RF receiver system is provided having a plurality of selectable antennas. The system includes a receiver for receiving RF signals from one of the plurality of antennas at a time. The receiver includes processing circuitry for processing the RF signals and generating a control signal to control selection of one of the antennas at a time. The system further includes a switched diversity module having a plurality of switches coupled to the plurality of antennas for selecting one of the antennas at a time. The switched diversity module further includes logic receiving the control signal generated by the receiver and generating logic output signals to control selection of one of the antennas at a time.

RF receiver system having switched antenna diversity module

A phase compensation circuit, for use with an FM reception system, includes a delay circuit and a control circuit. The delay circuit receives a composite input signal that exhibits a variable phase error and provides a plurality of selectable discrete delays. The control circuit is coupled to the delay circuit and receives a control signal whose value corresponds to the phase error associated with the composite input signal. The control circuit selects one of the plurality of selectable discrete delays responsive to the control signal, which is utilized to delay the composite input signal to provide a phase compensated composite output signal.

Phase compensation circuit

A mobile weather band radio and method of tuning the radio to select a signal channel based on geographic position. The radio has a weather band tuner adjustable for a plurality of radio wave signal channels. A position indicative receiver is provided for receiving position indicative signals and determining a current position of the radio. A controller automatically tunes the tuner to a select signal channel based on the determined geographic region.

Weather band radio and method of tuning same

A mobile weather band radio and method with dynamic geographic message updating. The radio has a weather band tuner for receiving weather band signals containing a message and a geographic identification code. A position indicative receiver is provided for receiving position indicative signals and determining a current position of the radio. Geographic identification codes and electronic map data are stored in memory for defining geographic regions corresponding to the geographic identification codes. A controller determines one of the geographic codes corresponding to the determined current position based on the position indicative signals, and further performs an operation, such as playing the message, when the determined geographic code corresponds to the received geographic code.

Mobile weather band radio and method

A technique for the automatic alignment and tuning of the front end of a vehicle radio. A tuning voltage is applied to a multiplying digital-to-analog converter before being applied to a front end tuning circuitry of the radio. A tuning voltage antenna number is applied to the tuning voltage at the converter to scale the tuning voltage, and adjust the center frequency tuning of the front end. During alignment, the tuning voltage antenna number is used to modulate the tuning voltage around a mean by reprogramming the tuning voltage antenna number a few values higher and lower in sequence. This modulation of the antenna tuning voltage creates an AC modulation component on the signal strength indicator signal passing through the front end. The signal strength indicator signal is measured and compared to its value before the tuning voltage antenna number was changed. If the signal strength indicator signal is higher for a higher tuning voltage antenna number, the front end is misaligned to the low side of the desired alignment point. Likewise, if the signal strength indicator signal is lower for an increasing tuning voltage antenna number, the front end is misaligned to the high side. If there is no change in the signal strength indicator signal for both increases and decreases in the tuning voltage antenna number, the front end is optimally aligned.

Low cost digital automatic alignment method and apparatus

A technique for reducing FM intrusion in an AM section of an AM/FM receiver. In one embodiment, a first switch is provided between an FM tuner filter circuit and an AM tuner circuit. A second switch is provided between the FM tuner circuit and a reference potential. When the receiver is in an FM mode, the first switch is closed so that a tuning voltage can be applied to the FM tuner circuit, and the second switch is open to prevent the tuning voltage from being affected by the reference potential. When the receiver is switched to the AM mode, the first switch is open to prevent intermodulation product signals generated by the FM tuner circuit from reaching the AM tuner circuit, and the second switch is closed to connect the FM tuner circuit to the reference potential. By connecting the FM tuner circuit to the reference potential when the receiver is in the AM mode, the tuning of the FM tuner circuit is shifted out of the FM bandwidth, thus eliminating intermodulation products at the AM frequencies. In an alternate embodiment, a switch is provided to switch off the power to the FM front end when in the AM mode.

Method and apparatus for reducing FM intrusion in AM receivers

An AM stereo input signal is processed by an envelope detector, an in-phase detector and a quadrature phase detector to yield outputs which may carry short noise impulses. Each output is low pass filtered to derive an average signal level and each output is ratiometrically compared to the corresponding average to detect a tic or modulation substantially above the average. In response to a tic a hold circuit generates a flag for a period which depends on the quality of the input signal. A dual mode deemphasis and sample/hold circuit normally filters the audio signal in each channel and is effective for the duration of the flag to hold the existing signal in the circuit to blank out the noise impulse.

Noise blanking circuit for AM stero

An adaptive audio processor for stereo AM broadcast signals includes independent signal processing paths. Each path has a variable lowpass filter and a matrix and variable Q 10 kHz notch filter to form LEFT and RIGHT channel signals with a 10 kHz notched pass band determined by adjacent channel noise. A 10 kHz pass band signal representative of adjacent channel noise from one of the signal processing paths is compared to a reference to generate a correction signal that is fedback to control the lowpass and notch filters. The correction signal adjusts the pass band and Q of the lowpass and notch filters so that the effects of adjacent channel noise are minimized. Other receiver signals which are reflective of the quality of the received broadcast signal, e.g., the AGC signal, an excess modulation signal, and a receiver microprocessor signal are similarly employed to control the lowpass and notch filters.

Adaptive audio processor for AM stereo signals

A differential operational amplifier comprises a differential input circuit that provides a differential output signal to a plurality of independent output circuits. The gains of the differential input circuit and one output circuit are set by a fixed bias source. A variable bias source controlled by an external signal determines the gain of each other output circuit so that various attenuation characteristics are obtained in the other output circuits without affecting the operating conditions of the operational amplifier. A feedback element between the output of the one output circuit and the differential input circuit assures gain stability.

Multiple output operational amplifier

An ajustable switched capacitor circuit comprises a first stage, a second stage and a switched capacitor circuit coupling the output of the first stage to the input of the second stage. The operating parameters of the second stage are a function of the effective resistance of the switched capacitor coupling circuit. An attenuator interposed between the output of the first stage and the input of the switched capacitor coupling circuit controls the charging voltage of the switched capacitor coupler thereby controlling its effective resistance and parameters of the output stage. The signal loss through the attenuator is continuously adjustable responsive to an external control voltage to obtain continuous control of various output stage parameters. The output stage may comprise a filter having the parameters of its transfer function determined by the effective resistance of the switched capacitor coupling circuit.

Switched capacitor filters with continuous time control

An audio detector circuit forms L+R and L-R audio signals from an intermediate frequency compatible quadrature amplitude modulated signal in the form (1+L+R)cos(fct+.phi.) where .phi. contains phase modulated L+R and L-R signals. An envelope detector generates an L+R audio signal and in-phase and quadrature phase detectors produce L+R and L-R audio signals, respectively. The difference between L+R outputs of the envelope and in-phase detectors are amplified to generate a cosine correction signal. Each detector includes a differential operational amplifier having an field effect feedback transistor coupled between each amplifier output and the corresponding input and an field effect transistor coupling the compatible quadrature amplitude modulated signal to the operational amplifier inputs. The impedances presented by the feedback transistor are varied by the cosine correction signal to remove the cosine component of the compatible quadrature amplitude modulated signal while frequency multiplication at the IF frequency rate provides the correct phase audio signal for matrix and noise processing.

Compatible quadrature amplitude modulation detector system

An FM stereo radio circuit has an ultrasonic noise detector and an amplitude noise detector each for detecting impulse noise by developing an average noise signal and comparing the average noise signal with an attenuated value of the instantaneous noise signal to generate a noise flag. A dual mode circuit normally operates as a low pass filter for a deemphasis function and is switched by the noise flag to operate as a sample and hold circuit which blanks the noise pulse. The dual mode circuit uses a switched capacitance design and is driven by clock signals to serve as a filter. The clock signals are stopped by the noise flag to effect the sample and hold function.

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Kokomo, IN, United States of America

Jeffrey J Marrah