Abstract: In embodiments of the present disclosure, a method may include determining an ambient temperature of an oscillator. The method may also include estimating an approximate frequency of operation of the oscillator. The method may additional include determining a process-based compensation to be applied to a resonator of the oscillator based on the approximate frequency. The method may further include setting a capacitance of a variable capacitor coupled to the resonator in order to compensate for temperature-dependent and process-dependent frequency variation of the oscillator based on the ambient temperature and the process-based compensation.

Abstract: A method and system of fine timing synchronization for an OFDM signal. The OFDM signal is coarse timing synchronized, generating a synchronization sequence and a CFR (Channel Frequency Response). The synchronization sequence is removed. A correlation coefficient of the correlation between the CFR applied to a number of carriers and the number of carriers with different window shifts is calculated. The largest window shift corresponding to a downsampling factor is indicated by the lowest correlation coefficient greater than a threshold. The CFR is downsampled by the downsampling factor, and an inverse FFT is performed on the downsampled CFR with a reduced number of calculations reduced by the downsampling factor, transforming the CFR into a CIR. A fine timing synchronization position is determined from the CIR and is utilized by an FFT unit within an OFDM receiver to accurately receive OFDM symbols of the OFDM signal.

Abstract: Radio-frequency (RF) apparatus includes receiver analog circuitry that receives an RF signal and provides at least one digital signal to receiver digital circuitry that functions in cooperation with the receiver analog circuitry. The receiver analog circuitry and the receiver digital circuitry are partitioned so that interference effects between the receiver analog circuitry and the receiver digital circuitry tend to be reduced.

Abstract: Disclosed herein is a phase-locked circuit including: a phase-locked section including a voltage controlled oscillator having a capacitance bank and changing oscillation frequency according to voltage information, the phase-locked section phase-locking an oscillating signal of the voltage controlled oscillator to a reference signal; and a calibration section having a voltage correcting function for supplying an appropriate calibration voltage to the voltage controlled oscillator in performing frequency calibration for the voltage controlled oscillator; the calibration section including a counter circuit, a first storage circuit and a second storage circuit, a comparator circuit, a control circuit, a voltage generating circuit, and a processing circuit.

Abstract: A clock signal generating arrangement for a communication device generates a system clock signal at an output for use as a timing reference. The clock signal generating arrangement comprises a reference clock generator for generating a reference clock signal, a main clock generator for generating a main clock signal having a greater accuracy than the reference clock signal, a clock adjust circuit coupled to the reference clock generator for generating a compensated reference clock signal to compensate for error in the reference clock signal and a clock signal selector coupled to the reference clock generator the main clock generator and the clock adjust circuit.

Abstract: A wireless device comprising a plurality of chips may be operable to wirelessly communicate information between a plurality of chips via selectable directional antennas. Each of the chips may comprise one or more transmitters and receivers, and one or more integrated directional antennas communicatively coupled to the transmitters and/or receivers. The directional antennas may include patch antennas that may be configured to transmit signals in the direction of another chip intended to receive the transmitted signals. The patch antennas may be configured to transmit signals at a frequency matching a configured frequency of a directional antenna integrated on another of the plurality of chips intended to receive the transmitted signals. The directional antennas may include dipole antennas. The inter-chip communication may include baseband signals, radio frequency signals, and/or intermediate frequency signals. The plurality of chips may be integrated on a single package or on a plurality of packages.

Abstract: A system includes a first clock module, a global positioning system (GPS) module, a phase-locked loop (PLL) module, a cellular transceiver, and a baseband module. The first clock module generates a first clock reference. The GPS module operates in response to the first clock reference. The WLAN module operates in response to the first clock reference. The PLL module generates a second clock reference by performing automatic frequency correction (AFC) on the first clock reference in response to an AFC signal. The cellular transceiver receives radio frequency signals from a wireless medium and generates baseband signals in response to the received radio frequency signals. The baseband module receives the baseband signals, operates in response to a selected one of the first clock reference and the second clock reference, and generates the AFC signal in response to the baseband signals.

Abstract: A mobile station (14) transmits a signal after connection is established, by using the same number of subcarriers as the number of subcarriers equal to or smaller than a predetermined number used for transmitting a connection request signal (TCCH). A base station (12) detects the number of subcarriers used for transmitting the connection request signal (TCCH) (S106), and controls in accordance with the detected number of subcarriers the passband width of a bandpass filter having a passband with a variable width accommodating the predetected number of subcarriers, for separating a signal of the mobile station (14) falling within the passband from a received signal (S108).

Abstract: Methods and systems for coexistence in a multiband, multistandard communication system utilizing a plurality of phase locked loops (PLLs) are disclosed. Aspects may include determining one or more desired frequencies of operation of a transceiver, determining a frequency of unwanted signals such as spurs, intermodulation, and/or mixing product signals, and configuring the Plls to operate at a multiple of the desired frequencies while avoiding the unwanted signals. The desired frequencies may be generated utilizing integer, which may include multi-modulus dividers. The wireless standards may include LTE, GSM, EDGE, GPS, Bluetooth, WiFi, and/or WCOMA, for example. The frequencies may be configured to mitigate interference. Plls may be shared when operating in TOO mode, and used separately operating in FOO mode. One or more digital interface signals, zero exceptions on a transmitter spur emission mask, and sampling clocks for AOCs and/or DACs in the transceiver may be generated utilizing the PLLs.

Abstract: In embodiments of the present disclosure, a method may include determining an ambient temperature of an oscillator. The method may also include estimating an approximate frequency of operation of the oscillator. The method may additional include determining a process-based compensation to be applied to a resonator of the oscillator based on the approximate frequency. The method may further include setting a capacitance of a variable capacitor coupled to the resonator in order to compensate for temperature-dependent and process-dependent frequency variation of the oscillator based on the ambient temperature and the process-based compensation.

Abstract: Provided are a receiver and a receiving method for a scalable bandwidth in a mobile station of an Orthogonal Frequency Division Multiplexing (OFDM) system. The receiving method includes the steps of: (a) filtering a received RF signal; (b) oscillating a frequency according to a center frequency control signal to output a local oscillation frequency; (c) down-converting the filtered RF signal by using the local oscillation frequency; (d) scalable-filtering the down-converted signal while adjusting a bandwidth according to a bandwidth control signal; (e) controlling gain of the scalable-filtered signal; (f) converting the gain-controlled analog signal into a digital signal by using a sampling frequency matching with a corresponding bandwidth according to an ADC control signal; and (g) demodulating the converted digital signal, outputting the center frequency control signal, the bandwidth control signal, and the ADC control signal according to control information received from an upper layer.

Abstract: In one embodiment, a local oscillator (LO) is configured to generate an LO signal. A transmission line receives the LO signal from the local oscillator and transmits the LO signal. A first set of taps and a second set of taps tap the transmission line to receive the LO signal. A plurality of transceiver blocks are configured to receive and transmit a plurality of phase-shifted radio frequency signals. Each transceiver block is coupled to a first tap and a second tap. Each LO signal received for a transceiver block is received with a different phase. However, the same reference phase may be calculated from a first LO signal received from the first tap and a second LO signal received from a second tap. Each transceiver block receives the reference LO signal having the reference phase determined from the first LO signal and the second LO signal.

Abstract: An approach is providing for supporting broadcast transmission of low density parity check (LDPC) coded signals. A receiver includes a decoder configured to decode an LDPC signal to output a decoded signal. The decoder is further configured to operate as an encoder; as such, interference cancellation can be implemented by the encoder re-encoded the received decoded signal. The above approach has particular applicability to satellite broadcast systems.

Abstract: A radio communication device includes a radio transmitting unit that generates a transmission signal containing a transmission carrier, a radio receiving unit including a frequency conversion circuit that performs down-conversion of a received signal containing a received carrier with substantially equal frequency to the transmission carrier, a transmission/reception separating circuit including a first port connected to the radio transmitting unit, a second port to the radio receiving unit and a third port to an antenna, that outputs the transmission signal into the first port to the third port and the received signal into the third port to the second port, and a transmission power control unit that performs control related to a transmission power of the transmission signal based on a low-frequency signal obtained by supplying a leakage component of the transmission signal leaking from the first port to the second port to the frequency conversion circuit and down-converting it.

Abstract: A receiver with transmit (TX) signal cancellation is disclosed. In an exemplary design, an apparatus includes an adjustment circuit, a transformer (e.g., a balun), and a low noise amplifier (LNA). The adjustment circuit receives a version of a TX signal and provides an adjusted TX signal, which may have adjustable amplitude and/or phase. The transformer receives the adjusted TX signal and a receive (RX) signal including a leaked TX signal, attenuates the leaked TX signal in the RX signal based on the adjusted TX signal, and provides an output RX signal. The TX signal may be transmitted via a primary antenna, and the RX signal may be received via a diversity antenna. The LNA receives the output RX signal and provides an amplified RX signal. The adjustment circuit detects remaining TX signal in the amplified RX signal and adjusts the amplitude and/or phase of the adjusted TX signal to reduce the remaining TX signal.

Abstract: A wireless device comprising a plurality of chips may be operable to dynamically configure wireless communication between the plurality of chips. Each of the chips may include one or more transceivers and one or more integrated directional antennas communicatively coupled to the one or more transceivers. The communications link between chips in the wireless device may be dynamically configured via control of the transceivers and/or the integrated directional antennas. The antennas may include patch antennas and/or dipole antennas. The transceivers may be configured by controlling output power of power amplifiers or by controlling gain of low noise amplifiers. The communications link may be dynamically configured by controlling a characteristic impedance of the antennas for impedance matching to transceivers. A frequency of the communication link may be controlled by configuring the antennas. A bandwidth of the communications link may be configured based on activity of processors in the wireless device.

Abstract: Certain embodiments of the present disclosure provide a method for frequency-domain gain control in system utilizing orthogonal frequency division multiplexing (OFDM) multiple input multiple output (MIMO). The proposed method reduces the complexity of the system while maximizing the internal accuracy of the OFDM MIMO decoder and preserving the performance of the system.

Abstract: A method for compensating a transceiver for impairments includes transmitting a plurality of partial bandwidth training signals using a transmitter. A plurality of response signals of a receiver having a bandwidth and exhibiting receiver impairments is captured. Each response signal is associated with one of the partial bandwidth training signals. Each of the partial bandwidth training signals is associated with a portion of the receiver bandwidth. A plurality of partial compensation filters is generated based on the plurality of response signals. Each partial compensation filter is associated with one of the response signals. The partial compensation filters are combined to configure a receiver compensation filter operable to compensate for the receiver impairments.

Abstract: According to one aspect of the present invention, an apparatus is provided to enable weather band radio signals to be received and processed using a digital signal processor (DSP). The DSP can include functionality to implement both frequency modulation (FM) demodulation and weather band data demodulation, i.e., specific area encoding (SAME) demodulation. In one such embodiment, soft decision samples of a SAME message can be combined, and based on a combined result, a hard decision unit can generate a bit value of weather band data.

Abstract: A communications system comprising at least one Base Station BS, one or more Satellites and Mobile Stations MS connected therebetween, and wherein the mobile station includes means to calculate Doppler frequency shifts. In a preferred embodiment, the mobile station includes means to measure clock mismatch frequency.

Abstract: A wireless device comprising a plurality of chips may be operable to communicate wireless signals via a mesh network comprising a plurality of integrated directional antennas on the plurality of chips. Wireless signals may be communicated between the plurality of the chips and/or with devices external to the wireless device via the mesh network. Beam-formed wireless signals may be communicated via the plurality of integrated directional antennas. The plurality of chips may be integrated on a single package or on a plurality of packages, which may comprise one or more circuit boards. Wireless signals may be communicated with devices external to the single package via the mesh network. The directional antennas may comprise patch antennas and/or dipole antennas.

Abstract: Variable operating currents are generated in relation to input signal power and output signal power and achieving both low noise and low power consumption. Emitter follower circuits are attached to output terminals of a frequency divider for generating a local signal. By adjusting the currents flowing through the emitter follower circuits, the amounts of currents flowing into mixers is adjusted. When the amounts of currents of local signals flowing into the mixers increases, the effect of noise suppression is expected. The amounts of the currents flowing through the emitter follower circuits is changed depending on the amplification factor of variable amplifiers.

Abstract: A first device transmits data over a first branch of a communications link toward a second device. That second device loops the received data pattern back over a second branch of the communications link. A bit error rate of the looped back data pattern is determined and a pre-emphasis applied to the transmitted data pattern is adjusted in response thereto. The first device further perturbs the data pattern communications signal so as to increase the bit error rate. The pre-emphasis is adjusted so as to reduce the determined bit error rate in the looped back data pattern in the presence of the perturbation. The steps for perturbing the signal and adjusting the pre-emphasis are iteratively performed, with the perturbation of the signal increasing with each iteration and adjustment of the pre-emphasis being refined with each iteration. The signal is perturbing by injecting modulation jitter into the signal (increasing each iteration) and adjusting amplitude of the signal (decreasing each iteration).

Abstract: Systems and devices for controlling frequency drift in satellite broadcast systems. A receiver antenna system for a direct broadcast satellite signal communications system in accordance with one or more embodiments of the present invention comprises an oscillator, a mixer, coupled to the oscillator, for converting satellite signals at a first frequency to signals at an intermediate frequency, an analog-to-digital (A/D) converter, coupled to the mixer, for receiving the signals at the intermediate frequency and for converting the signals at the intermediate frequency at near-real-time to a digital data stream, a Digital Signal Processor (DSP), coupled to the A/D converter, for processing the digital data stream, and a drift estimator, coupled to the DSP, the drift estimator determining a frequency drift of the oscillator, wherein the receiver antenna system corrects the frequency drift of the oscillator using the determined frequency drift.

Abstract: An apparatus and method for non-calibrated Automatic Frequency Correction (AFC) of a portable terminal are provided. The method includes identifying, by the portable terminal, signal strengths of signals received from neighboring base stations of a cell in which the portable terminal is currently located; searching for a frequency burst serving that provides synchronization acquisition information for synchronization with a base station; determining to perform the AFC according to a result of the searching for the frequency burst; and storing AFC data extracted through the AFC.

Abstract: One aspect of the invention includes a communication system that includes a tone generator configured to generate a first tone, a second tone, and a third tone. The third tone can have a frequency that is a harmonic product of at least one of the frequencies of the first and second tones. A transmitter that includes a predistortion system transmits a test signal comprising the first, second, and third tones. A receiver that is communicatively coupled to the transmitter receives and processes a received test signal corresponding to the test signal. The system further includes a controller that generates a set of correction coefficients based on a measured interaction of the third tone with a non-linear signal component in the received test signal. The set of correction coefficients can be provided to the predistortion system for substantially linearizing communication signals transmitted from the transmitter.

Abstract: Apparatus and methods for improving the spectral performance of a polar modulator are described. A composite FM signal component of a composite polar transmit signal may be processed by monitoring the FM signal to detect a transient burst component, and, responsive to detection of a transient burst, generating a spectrally friendly replacement signal component that may be combined with the FM signal to improve spectral performance of the composite signal. In addition, an associated AM component of the composite transmit signal may be filtered to further improve spectral performance.

Abstract: A wireless terminal includes an antenna which comprises an antenna element and at least one frequency switching circuit to control an operating frequency of the antenna element in accordance with a frequency control signal, a plurality of RF circuits to perform an RF signal processing, an antenna switch to connect the antenna to one of the plurality of RF circuits in accordance with a connection control signal, and a generation unit configured to generate the frequency control signal and the connection control signal in accordance with switching between a plurality of wireless communication systems or switching between transmission and reception.

Abstract: A method and device for frequency deviation pre-correction are provided. The method includes: estimating an uplink frequency deviation value of a terminal, and obtaining a historic value of the uplink frequency deviation pre-correction that has been used for the frequency deviation pre-correction of the terminal; according to the historic value of the uplink frequency deviation pre-correction, determining a current value of the uplink frequency deviation pre-correction of the terminal, the current value of the uplink frequency deviation pre-correction being closer to the uplink frequency deviation value than the historic value of the uplink frequency deviation pre-correction; by using the current value of the uplink frequency deviation pre-correction, pre-correcting the frequency deviation of the terminal, thereby the signal detection performance of the terminal can be effectively improved.

Abstract: A wireless communication system having a terminal unit operates in a reduced noise state during receipt of a wireless transmission from a control unit. The terminal unit includes terminal circuitry, a radio and noise management circuitry. The noise management circuitry partially or fully disables operation of the terminal circuitry during a receipt by the radio. Noise management circuitry may disable a terminal processor, disable interrupts, buffer interrupts and otherwise modify operation of the terminal circuitry to reduce generated radio noise that would otherwise interfere with receipt of data by the radio. The wireless communication system includes noise management circuitry located in a control unit that operates in conjunction with noise management circuitry in a first terminal unit and a second terminal unit to schedule transmissions from the control unit. These scheduled transmissions allow the terminal units to perform required processing functions outside of the reduced noise period.

Abstract: An apparatus and a method for acquiring synchronization to support multi-frequency in a mobile communication terminal are provided. The apparatus includes a frequency generator, a control signal generator and at least two modems for operating respective Frequency Allocations (FAs) by sharing the frequency generator and the control signal generator. In an embodiment, the frequency generator respectively receives first reference frequency clock signals from an oscillator of each of the at least two modems and generates a second reference frequency clock signal and the control signal generator outputs a signal for controlling the oscillator of each of the at least two modems according to a frequency offset value estimated in each of the at least two modems.

Abstract: A portable wireless communication apparatus is provided with antenna elements; a mobile phone signal processing circuit; a DTV tuner for receiving DTV low-band frequency signals and DTV high-band frequency signals; impedance matching circuits for the mobile phone signal processing circuit; and impedance matching circuits for the DTV tuner for receiving the DTV low-band frequency signals and DTV high-band frequency signals. A switch is changed to select either the DTV low-band frequency signals or the DTV high-band frequency signals, and output the selected signals to the DTV tuner. A tuner controller controls the switch to select the DTV high-band frequency signals by using the antenna element for transmission from the mobile phone signal processing circuit.

Abstract: A method for verifying alignment between first and second integrated devices coupled together using a reference and a coupling capacitor, including: transmitting a reference signal on a transmission electrode of the reference capacitor; receiving a coupling signal on a reception electrode of the reference capacitor; amplifying the coupling signal, generating a reception reference signal; generating a reception control signal as a function of the reception reference signal; transmitting a communication signal on an electrode of the coupling capacitor; receiving a reception signal on an electrode of the coupling capacitor; amplifying the reception signal, generating a first compensated signal; controlling a level of amplification of amplifying the coupling signal and the reception signal as a function of the reception control signal; and detecting a possible misalignment between the first and second devices based on an amplitude of the communication signal and an amplitude of the compensated signal.

Abstract: CDMA code channels are acquired using a crystal oscillator that is not temperature compensated and that generates a tuning signal with relatively large frequency error (e.g., +/?5 ppm). Channel acquisition is first attempted at no offset from a start frequency that is obtained by fitting an ideal temperature/frequency error curve to available actual data points. Following unsuccessful pilot acquisition, the offset frequency is stepped in a “spiral” manner, and pilot acquisition is retried. When the pilot and synchronization channels are successfully acquired, but the system identification is unexpected, an adjacent channel image has been acquired, and the offset frequency is bumped by a large step (e.g., 15 kHz). Pilot acquisition is retried using spiral stepping. The crystal oscillator is calibrated after each successful acquisition of the pilot, synchronization and paging channels by retaining a data point in a frequency adjustment table for the temperature at which frequency acquisition was successful.

Abstract: Harmonic control apparatus of radio frequency (RF) devices are provided including an active device. In particular, the harmonic control apparatus includes a complementary open-loop resonator that is integrated in a conducting pattern of the harmonic control apparatus, to produce a shunt resonator that is configured to act as a short-circuit termination on at least one tuned frequency.

Abstract: The present invention relates to a quadrature divider which may be used in a phase locked loop or frequency synthesizer or with a single side band mixer. According to a preferred embodiment the divider takes a quadrature input and has a quadrature output. The divider has four analog mixers 1, 2, 3 and 4. The first two mixers 1, 2 take the in-phase quadrature input, while the second mixers 3, 4 take the quadrature-phase quadrature input. The outputs and feedback loops of the mixers are properly arranged such that the in-phase and quadrature-phase outputs of the divider have a determinisitic phase sequence relationship based on the phase sequence relationship of the corresponding quadrature inputs. Third order harmonics may be minimized or reduced by addition or subtraction of the mixer outputs. As the divider is able to take a quadrature input, there is no need for a dummy divider in the phase locked loop, thus saving space and power.

Abstract: Disclosed herein is a phase-locked circuit including: a phase-locked section including a voltage controlled oscillator having a capacitance bank and changing oscillation frequency according to voltage information, the phase-locked section phase-locking an oscillating signal of the voltage controlled oscillator to a reference signal; and a calibration section having a voltage correcting function for supplying an appropriate calibration voltage to the voltage controlled oscillator in performing frequency calibration for the voltage controlled oscillator; the calibration section including a counter circuit, a first storage circuit and a second storage circuit, a comparator circuit, a control circuit, a voltage generating circuit, and a processing circuit.

Abstract: An exemplary embodiment of the present invention described and shown in the specification and drawings is a transceiver with a receiver, a transmitter, a local oscillator (LO) generator, a controller, and a self-testing unit. All of these components can be packaged for integration into a single IC including components such as filters and inductors. The controller for adaptive programming and calibration of the receiver, transmitter and LO generator. The self-testing unit generates is used to determine the gain, frequency characteristics, selectivity, noise floor, and distortion behavior of the receiver, transmitter and LO generator. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: There is provided a method for generating an error signal for an automatic frequency control (AFC) loop in a Code Division Multiple Access (CDMA) system. Sign information relating to phase differences in received pilot signals is accumulated. In one embodiment, the accumulated sign information is compared against predetermined threshold levels. The error signal is generated when at least one of the predetermined threshold levels is satisfied. In a second embodiment, the accumulated sign information is decimated. An output of the decimating step is utilized as the error signal for the AFC loop.

Abstract: According to one embodiment, a compact low-power receiver comprises a front-end producing a front-end gain and a back-end producing a back-end gain. The front-end includes a transconductance amplifier providing digital gain control and outputting an amplified receive signal, a mixer for generating a down-converted signal from the amplified receive signal, and a transimpedance amplifier (TIA) including a current mode buffer. The TIA provides gain control for amplifying the down-converted signal to produce a front-end output signal. In one embodiment, the back end includes a second-order low-pass filter to produce a filtered signal from the front-end output signal and an analog-to-digital converter (ADC), wherein the filtered signal is fed directly to the ADC without direct-current (DC) offset cancellation being performed. In various embodiments, the front-end gain is substantially greater than the back-end gain.

Abstract: According to an embodiment, a communication device of the embodiment includes: a reference frequency generating unit configured to generate a reference frequency having a deviation from center frequency deviation under a predetermined condition, a radio signal detection unit configured to operate in a detection period based on the reference frequency and detect a periodic radio signal generated based on a reference frequency having higher precision than the precision of the reference frequency. The radio signal detection unit corrects the detection period by using the periodic signal.

Abstract: A radio communication transceiver includes a transformer, a switch, a power amplifier (AP), and a low noise amplifier (LNA). The transformer has a primary winding and a center-tap secondary winding, the primary winding has a first endpoint and a second endpoint, and the center-tap secondary winding has a first endpoint, a second endpoint, and a third endpoint. The switch has a gate, a drain, and a source, in which the gate receives a control signal (CS), the drain is connected to the second endpoint of the primary winding of the transformer through a coupling capacitor, and the source is grounded. The PA has at least one output terminal connected to the first endpoint and the second endpoint of the center-tap secondary winding of the transformer. The LNA has an input terminal connected to the second endpoint of the primary winding of the transformer.

Abstract: Techniques for mitigating VCO pulling are described. In an aspect, VCO pulling may be mitigated by (i) injecting an oscillator signal, which is a version of a VCO signal from a VCO, into a transmitter and (ii) using coupling paths from the transmitter to the VCO to re-circulate the oscillator signal back to the VCO. In one design, an apparatus includes a VCO and a coupling circuit. The VCO generates a VCO signal at N times a desired output frequency. The coupling circuit receives an oscillator signal generated based on the VCO signal and injects the oscillator signal into a transmitter to mitigate pulling of the frequency of the VCO due to undesired coupling from the transmitter to the VCO. The apparatus may include a phase adjustment circuit that adjusts the phase of the oscillator signal and/or an amplitude adjustment circuit that adjusts the amplitude of the oscillator signal.

Abstract: Embodiments related to the setting of an operating point of an amplifier are described and depicted.

Abstract: A method for automatically tuning a frequency modulator in a mobile device is described. A frequency band is automatically scanned using a frequency modulation (FM) receiver. The FM receiver is integrated as a part of the mobile device. Quality associated with channels of the frequency band is analyzed to identify at least one available channel at a first frequency. The first frequency is assigned to an FM modulator. The FM modulator is integrated as a part of the mobile device. A determination is made whether a command to scan for a second frequency is received. If the command to scan for the second frequency is not received, a signal on the first frequency is transmitted by the FM modulator.

Abstract: A demodulation section 13 receives a TDMA-TDD based phase-modulated burst signal of mobile communications and demodulates the burst signal by a synchronous detection system (or a quasi-synchronous detection system). The demodulation section 13 includes a frequency deviation compensation section and a carrier recovery section each having a loop filter 14 with three or more stages of time constants. The time constants are switched by a selector switch 15 based on a control signal from a demodulation control section 16. This achieves quick pull-in and jitter after convergence is minimized, thereby allowing highly efficient performance of frequency deviation compensation, etc. that is required for synchronous detection (or quasi-synchronous detection) without increasing the size of circuit.

Abstract: A wireless communications device, e.g., a mobile node supporting direct peer to peer communications, performs a self-calibration of one or more of: receiver IQ imbalance, transmitter IQ imbalance, receiver DC offset, and transmitter DC offset. The wireless communications device, operating in calibration mode, intentionally sets the oscillator frequency used for downconversion in its receiver module to a different frequency than the oscillator frequency used for upconversion in its transmitter module. A first baseband signal, e.g., a single tone test signal, is input to the transmitter module and an upconverted transmit signal is generated. The transmit signal is routed via a feedback loop to the receiver, which performs a downconversion operation. Power and/or phase measurements of the signals output from the downcoversion are used to determine IQ imbalance compensation information and DC offset compensation information.

Abstract: A base station for compensating for frequency offsets is described. The base station includes a processor and instructions stored in memory. The base station computes a time domain impulse response estimate and applies frequency offset compensation to the time domain impulse response estimate to obtain a time domain offset-compensated impulse response estimate. A frequency domain offset-compensated impulse response estimate is computed. The frequency domain offset-compensated impulse response estimate is used to compute beamforming weights. The base station transmits data using the beamforming weights.

Abstract: An apparatus including a first circuit, a second circuit, a third circuit, and a fourth circuit. The first circuit may be configured to generate a demodulated signal in response to a modulated signal and a seed value selected in response to a first control signal. The second circuit may be configured to generate a second control signal in response to the demodulated signal. The third circuit may be configured to generate the first control signal in response to the second control signal, a compensation signal, and the first control signal, where generation of the first control signal includes adding the second control signal, the compensation signal, and a latched version of the first control signal. Generation of the latched version of the first control signal may include sampling the first control signal in response to a clock signal. The compensation signal may compensate for variation in the clock signal.

Abstract: A system and method providing variable-frequency IF conversion in a multimode communication device. Various aspects of the present invention provide a multimode communication device comprising at least one RF signal receiver adapted to receive at least a first RF signal corresponding to a first communication protocol and a second RF signal corresponding to a second communication protocol. A controllable frequency source may, for example, be adapted to output a mixing signal characterized by one of a plurality of selectable frequencies. Such selectable frequencies may, for example, comprise a first frequency corresponding to the first communication protocol and a second frequency corresponding to the second communication protocol. A mixer may, for example, receive a received RF signal from the RF signal receiver, receive a mixing signal from the controllable frequency source, and convert the received RF signal to an IF signal utilizing the received mixing signal.