Abstract: A spread spectrum detector employs a Doppler phase correction system that improves correlation of pseudo-noise (PN) codes to a received spread spectrum signal by combining phase shifts to correlation values, using a fast fourier transform (FFT), that compensate for the Doppler shift error that is inherent in the signal and that is imposed upon the signal by movement between the signal source and receiver. In architecture, the Doppler phase correction system includes a receiver to receive a spread spectrum modulated signal having the Doppler shift error. A multiplier produces a plurality of complex first correlation values based upon the signal and a code. A phase shifter generates a plurality of complex second correlation values respectively from the first correlation values using an FFT.

Abstract: A signal processing system control method and apparatus are described. Various embodiments include a signal processing system with multiple subsystems. A method for controlling the signal processing system includes storing channel records in a designated area of shared memory. A channel records include channel data which includes one of multiple discrete signals to be processed by multiple subsystems in a time-multiplexed manner. The channel record includes information used by the multiple subsystems to process a channel, including information used to configure the multiple subsystems, information used to allocate the shared memory, and information used to communicate between multiple subsystems.

Abstract: A method and system for dynamic memory allocation and sharing in electronic systems. Embodiments include multi-channel signal processing, including continuously receiving multiple channels, wherein each channel comprises a discrete signal, and processing the multiple channels in a signal processing component on a time-multiplexed basis. Processing the multiple channels includes configuring the signal processing component for one of a plurality of operational modes, including allocating a memory into areas for storage of types of data, wherein certain areas are accessed by certain signal processing subsystems in certain manners. Configuring includes configuring the signal processing component to operate in different modes concurrently for different channels.

Abstract: A receiver capable of receiving a spread spectrum signal and having a crosscorrelator that enables a carrier wave (CW) jamming to be identified, tracked, replicated and removed from the received spread spectrum signal after demodulation of a weak signal has occurred.

Abstract: A cancellation system may utilize a system architecture that delays the received signals and cancels less than all the received signals from the delayed version of the received signals. An implementation of this system architecture may include a delay circuit, a demodulation and despreader unit, a re-modulator and re-spreader unit and a combiner. The delay circuit produces a delayed version of the received signals and the demodulator and de-spreader unit produces a demodulated and de-spread signal corresponding to one of the received signals. The respreader and remodulator unit produces a remodulated and respread signal from the demodulated and despread signal and the combiner produces a combined signal from the delayed version of the received signals and the remodulated and respread signal. The cancellation system may also utilize a system architecture that stores the received signals and cancels less than all the received signals from the stored version of the received signals.

Abstract: Implementation of an improved matched filter system for despreading a PN code from a spread spectrum signal utilizes a matched filter system that may be broadly conceptualized as a system that optimizes the number of multipliers and adders utilized by the system in despreading a PN code from a spread spectrum signal. This lowers the power consumption of the improved matched filter system and increases the speed at which the system despreads the PN code from the spread spectrum signal.

Abstract: Implementation of an improved matched filter system for despreading a PN code from a spread spectrum signal utilizes a matched filter system that may be broadly conceptualized as a system that optimizes the number of multipliers and adders utilized by the system in despreading a PN code from a spread spectrum signal. This lowers the power consumption of the improved matched filter system and increases the speed at which the system despreads the PN code from the spread spectrum signal.

Abstract: The invention is directed to a personal communications device with a ratio counter providing tracking transitioning edges of two clocks so as to generate a signal to initiate capture of a clock cycle count. Provisions for tracking the transitioning edges include a storage memory for storing a first and a second value selected in accordance with the principles of convergents of continued fractions. A first and second counter each responding to first and second clock signal, respectively. The first and second counter each count clock cycles of the respective clock signal. A first register for capturing the count of the first counter and a second register for capturing the count of the second counter.

Abstract: A data detection circuit within a global positioning system (GPS) satellite receiver operates to detect and decode data sent in a spread spectrum signal. The data detection circuit receives input from a radio receiver, the information containing data from a plurality of satellites. The data is supplied to a circular memory device, which determines which data corresponds to which satellite. The memory device sends the received signal to a matched filter, which decodes the signal received from each satellite. This signal is analyzed to determine whether a phase inversion due to data modulation on the received signal is present. The phase inversion can occur at boundaries, known as data epochs, in the received signal, and corresponds to data in the received signal. This data contains information relating to the position of each satellite and is collected by the data detection circuit for use by the GPS receiver.

Abstract: A mobile communications device using a common oscillator for communication and global positioning system (GPS) functions. In one embodiment, a communications unit receives a precision carrier frequency signal from a source and generates a reference signal that is used to calibrate a common oscillator.

Abstract: Communications systems, and particularly portable personal communications systems, such as portable phones, are becoming increasingly digital. One area that has remained largely analog, however, is the modulation and RF amplifier circuits. To produce a RF frequency waveform. An output of a class D amplifier is coupled to an integrator to create an analog signal. A resonant circuit shapes an output waveform based on the analog signal to create a sinusoidal RF broadcast signal. The waveform of the class D amplifier may be duty cycle modulated. Digital modulation may occur using a digital sigma delta modulator or a digital programmable divide modulator. Using the digital modulation techniques and class D amplification techniques together allows for broadcast a PSK signal that has been decomposed into amplitude and phase components.

Abstract: A data detection circuit within a global positioning system (GPS) satellite receiver operates to detect and decode data sent in a spread spectrum signal. The data detection circuit receives input from a radio receiver, the information containing data from a plurality of satellites. The data is supplied to a circular memory device, which determines which data corresponds to which satellite. The memory device sends the received signal to a matched filter, which decodes the signal received from each satellite. This signal is analyzed to determine whether a phase inversion due to data modulation on the received signal is present. The phase inversion can occur at boundaries, known as data epochs, in the received signal, and corresponds to data in the received signal. This data contains information relating to the position of each satellite and is collected by the data detection circuit for use by the GPS receiver.

Abstract: A communication system for the wireless transmission of information through a single antenna is disclosed. The communication system comprises a handset and one or more modules capable of being coupled to the handset. The handset processes baseband information signals being received and transmitted, and transmits and receives radio frequency (RF) information signals through its antenna. Each module is removably couplable to the handset for converting baseband information signals into RF information signals for transmission, and for converting received RF information signals into baseband information signals. Each removably couplable module is optimized to enable wireless communication in accordance with at least one communication standard when coupled to the handset. By coupling the appropriate module with the handset, wireless communication in a number of geographic locations may be achieved.

Abstract: The invention is directed to a personal telecommunications device having both global positioning systems (GPS) and telecommunications provisions which share a common clock source. GPS provisions include a feedback loop for controlling an oscillator that generates a GPS system signal based upon the common clock signal. The feedback loop includes a frequency synthesizer for generating a feedback control signal, a phase comparator for generating a control signal in accordance with the feedback signal and the common clock signal, and a loop filter for processing and outputting the control signal to the oscillator to control the frequency of GPS system signals.

Abstract: The invention discloses a system for improving performance of the RF amplification stage of communication receivers by accounting for the signal environment of the RF amplifier. The linearity, gain and power supply voltage of the RF amplification stage of the communication receiver is adjusted to produce an optimal signal into the succeeding narrow-band amplification stage(s). The adjustment of the RF stage includes mechanisms such as adjusting the RF amplifier power supply level using a DC to DC converter. It also includes allowing distortion in the RF amplification stage if the distortion in the RF amplification stage does not affect the target signal. For example, if there were a strong signal that fell within the same band as the target signal, amplification would be allowed to be so high that it distorted the undesired signals, but not the tined signals.

Abstract: Embodiments of the invention are used to improve performance of spread spectrum communications equipment. The improvement may take the form of improved sensitivity to weak signals, quicker acquisition time of weak signals, or the reduction of multipath interference. To acquire a spread spectrum signal PN codes are commonly compared with the spread spectrum signal. This comparison is often in reality a successive series of comparisons with the same code. Successive comparisons are often carried out in a process called hypothesis testing by which the correlated output of the spread spectrum signal and the PN code must pass a series of thresholds. This method is adopted to prevent identifying a PN code as being present based on a spurious correlation value. This method of successive comparisons also prevents a low correlated value from being rejected immediately thereby helping assure that signals with low signal strength can be identified also.

Abstract: Modern digital integrated circuits are commonly synchronized in their workings by clock circuits. The clock frequency for a circuit must take into account the propagation delay of signals within the critical path of the circuit. If the clock time is not adequate to allow propagation of signals through the critical path, improper circuit operation may result. The propagation delay is not a constant from circuit to circuit, and even in a single circuit may change due to temperature, power supply voltage and the like. Commonly, this variation is handled by assuming a worse case propagation delay of the critical path, and then designing the clock frequency and minimum power supply voltage of the circuit so that the circuit will function under worst case conditions.

Abstract: A cell phone is provided that may be used with multiple radio formats, such as GSM and CDMA. The cell phone includes a receiver that receives radio signals and converts them into electrical signals. An analog to digital converter is connected to the receiver and converts an analog input to a digital output having an adjustable number of bits at an adjustable sampling frequency. A cell phone application specific integrated circuit is connected to the analog to digital converter, which is used to process the digital output to extract encoded telecommunications data in one of the supported radio formats.

Abstract: The invention discloses a system for improving performance of the RF amplification stage of communication receivers by accounting for the signal environment of the RF amplifier. The linearity, gain and power supply voltage of the RF amplification stage of the communication receiver is adjusted to produce an optimal signal into the succeeding narrow-band amplification stage(s). The adjustment of the RF stage includes mechanisms such as adjusting the RF amplifier power supply level using a DC to DC converter. It also includes allowing distortion in the RF amplification stage if the distortion in the RF amplification stage does not affect the target signal. For example, if there were a strong signal that fell within the same band as the target signal, amplification would be allowed to be so high that it distorted the undesired signals, but not the tined signals.

Abstract: Communications systems, and particularly portable personal communications systems, such as portable phones, are becoming increasingly digital. The tendency towards digital systems has come about, in part, because digital systems may operate on less power than their analog counterparts. One area that has remained largely analog, however, is the modulation and RF amplifier circuits. To produce a RF frequency waveform a class D switching type amplifier is used. The output of the class D amplifier is coupled to an integrator, to create an analog signal. The analog signal coupled to a resonant circuit, to shape the output waveform into a sinusoidal RF broadcast signal. The waveform of the class D amplifier is duty cycle modulated by a combination signal representing the combination of desired amplitude modulation of the broadcast signal and the desired average power level desired.