Abstract: A squaring circuit has current mode triplet metal oxide semiconductor (MOS) devices, including a first MOS device, a second MOS device and a third MOS device each having a source operably coupled to a first current source; and a fourth MOS device, a fifth MOS device and a sixth MOS device each having a source operably coupled to a second current source. The drain of first and fourth MOS device is operably coupled to a first supply, the drain of second and fifth MOS device is operably coupled to a first differential output port and the drain of third and sixth MOS device is operably coupled to a second differential output port. The gate of first, second and sixth MOS device is connected to a first differential input port, and the gate of third, fourth and fifth MOS device is connected to a second differential input port.

Abstract: Detection of a confusion caused by scrambling code reuse is provided herein. Timing measurements, as observed by a mobile device, and an identification of primary scrambling codes associated with the timing measurements are captured. The timing measurements are identified by the primary scrambling codes for the particular radio measured. The mobile device also reports its location information. Radios for which timing measurements have been received are paired. Based on the paired radios and a history of observed time difference reference values for radio pairs, comparisons are made between paired radios having at least one common radio. Radios, exhibiting a set of values that is near an expected range, are removed from the analysis. Radios, exhibiting two sets of values that are distinct, are isolated in order to identify the radio that is causing the scrambling code confusion.

Abstract: Detection of a faulty radio oscillator is provided herein. Also provided herein is detection of faulty mobile timing measurements. Timing measurements, as observed by a mobile device, and an identification of primary scrambling codes associated with the timing measurements are captured. The primary scrambling codes match each timing measurement with a particular radio. The mobile device can also report its location information. Radios for which timing measurements have been received are paired. Based on the paired radios and an associated observed time delay derived from the timing measurements, comparisons can be made between paired radios having at least one common radio. Radios exhibiting an expected timing value can be removed from the analysis in order to isolate a radio that has a faulty radio oscillator.

Abstract: Radio frequency (RF) architectures for spectrum access networks are provided. Embodiments of the invention generally provide a radio frequency (RF) architecture for customer premise equipment (CPE) for use in, for example, IEEE 802.22 wireless regional area networks (WRANs). In some embodiments, the CPE RF architecture includes two receive chains with a directional antenna and an omni-directional antenna, respectively. The CPE RF architecture facilitates opportunistic out-of-band spectrum sensing and WRAN signal receiving that are performed in parallel with data transmission.

Abstract: The present invention includes a method of determining a phase estimate for an input signal having pilot symbols. The method includes receiving a plurality of pilot symbols, and then multiplying two or more pilot symbol slots by corresponding correlator coefficients to correct a phase estimate of the input signal.

Abstract: The present disclosure relates to an active antenna array for a mobile communications network. The active antenna comprises a base band unit coupled to a base station, a plurality of transceiver units and at least one link. The plurality of transceiver units is terminated by at least one antenna element. The at least one link couples individual ones of the plurality of transceiver units to the base band unit 10. The at least one link is a digital link and is adapted to relay an individual transmit signal concurrently and in synchronisation with a transmit clock signal. The present disclosure further teaches a method for relaying radio signals in a mobile communications network. The present disclosure further relates to a computer program enabling a computer to manufacture the active antenna array of the present disclosure and to execute the method of relaying radio signal in a mobile communications system.

Abstract: One embodiment of the present invention relates to an apparatus for preventing remodulation in a transmission chain. A first offset generation circuit selectively introduces a first frequency offset into in-phase (I) and quadrature phase (Q) equivalent baseband signals. A second offset generation circuit selectively introduces a second frequency offset into an oscillator output signal. The frequency of the offset oscillator output signal is divided by a divider to form offset local oscillator signals, which are provided to up-conversion mixers that modulate the offset equivalent baseband signals onto the offset local oscillator signals to generate a composite modulated output signal. The first and second frequency offsets are chosen to have values that cancel during modulation. However, because the second frequency offset shifts the offset oscillator output signal's frequency to a value that is no longer a harmonic of the composite modulated output signal's frequency, remodulation is prevented.

Abstract: Techniques, apparatuses and systems for providing communications based on time reversal of a channel impulse response of a pulse in a transmission channel between a transmitter and a receiver to enhance reception and detection of a pulse at the receiver against various effects that can adversely affect and complicate the reception and detection of the pulse at the receiver.

Abstract: A receiver/transmitter and related receiving/method capable of simultaneously receiving/transmitting discontinuous frequency band signal components of an input/output signal are provided. Phase swapping on in-phase/quadrature-phase local oscillation differential signals is applied to frequency down-conversion of the input signal or frequency up-conversion of a baseband signal to be outputted to radio domain, and thereby achieve simultaneously receiving discontinuous frequency bands of the input signal and simultaneously sending different baseband signal components on discontinuous frequency bands of the output signal.

Abstract: A transmitter circuit includes a first synthesizer section, and a second synthesizer section which consumes less current than the first synthesizer section. The transmitter circuit performs switching such that the first synthesizer section is operated and the second synthesizer section is powered off in polar modulation, and the second synthesizer section is operated and the first synthesizer section is powered off in quadrature modulation, thereby reducing consumed power. While the first synthesizer section is operating, calibration for an oscillation frequency is performed, and when the operation is stopped, a calibration value is stored. When an operation of the first synthesizer section is restarted, the stored calibration value is corrected by using temperature change, thereby enhancing calibration accuracy and preventing degradation in quality of a transmission signal.

Abstract: The present disclosure teaches an active antenna array for a mobile communications network. The active antenna array comprises a base band unit, a plurality of transceiver units terminated by at least one antenna element; and at least one link. The link couples the individual ones of the plurality of transceiver units to the base band unit. The link is a digital link and is adapted to relay a payload signal at a selectable payload rate. The digital link is further adapted to relay a timing signal at a fixed timing rate, when the timing signal is embedded in the payload at a selectable payload rate. The present disclosure further teaches a method for relaying radio signals and a computer program for manufacturing the active antenna array and for executing the method.

Abstract: Improvements are disclosed for in-band signaling, i.e., transmission of data in a voice channel of a digital wireless network during a voice call session. A family of narrow-band signaling methods, some employing tapered waveforms, is disclosed to successfully pass data-carrying signals through the low-bit rate modes of the EVRC-B vocoder commonly used in CDMA wireless channels. These features can be used in cell phones or other wireless communication devices, including automotive applications.

Abstract: An apparatus for determining signal power comprise an oscillating circuit and a determining circuit. The oscillating circuit generates an oscillating signal. When a to-be-detected signal has signal power greater than a threshold, the oscillating signal has a first frequency; when the signal power is smaller than the threshold, the oscillating signal has a second frequency. The determining circuit determines whether the oscillating signal has either the first frequency or the second frequency, and generates a determination result accordingly.

Abstract: The radio transmitting apparatus includes a first initial phase value setting circuit that sets, in the first modulator, an initial value of the phase of the first modulated signal, which is a value at the start of the modulation according to the first modulation scheme. The radio transmitting apparatus includes a second initial phase value setting circuit that sets, in the second modulator, the phase stored in the phase storing circuit as an initial value of the phase of the second modulated signal, which is a value at the start of the modulation according to the second modulation scheme. The radio transmitting apparatus includes a signal gathering circuit that selects and outputs the first modulated signal output from the first modulator and then selects and outputs the second modulated signal output from the second modulator.

Abstract: A sigma-delta modulator includes a front portion and a hybrid portion to form a loop filter. The front portion includes integrator(s) and feed-forward path(s), and is arranged to provide a front signal by combining signals of the integrator(s) and feed-forward path(s). The hybrid portion is coupled to the front portion, and arranged to provide a filtered signal by combining an integration of the front signal and a weighting of the front signal. The filtered signal is quantized, converted from digital to analog, and fed back to the loop filter.

Abstract: A signal processing circuit comprises a frequency up-conversion circuit (14, 60) for performing up-conversion with a first local oscillator frequency and a frequency down-conversion circuit (16) for performing down-conversion with a second local oscillator frequency. A digital signal processor (10) controls supply first signals representing a first complex signal to the up-conversion circuit, and receives second signals representing a second complex signal. The digital signal processor controls a compensation of I/Q mismatch of results of up-conversion and/or down-conversion. The digital signal processor (10) switches to a calibration mode for selecting a parameter of said compensation. In the calibration mode the first and second local oscillator frequencies have a frequency offset with respect to each other.

Abstract: A radio-frequency (RF) apparatus, which may reside in a receiver or transceiver, includes receive-path circuitry. The receive-path circuitry includes a poly-phase filter and a harmonic filter. The poly-phase filter accepts an input signal and generates two output signals. One output signal of the poly-phase filter constitutes an in-phase (I) signal. The other output signal of the poly-phase filter constitutes a quadrature (Q) signal. The a harmonic filter couples to the poly-phase filter. The harmonic filter accepts as input signals the in-phase and quadrature output signals of the poly-phase filter.

Abstract: The present invention includes a method of determining a phase estimate for an input signal having pilot symbols. The method includes receiving a plurality of pilot symbols, and then multiplying two or more pilot symbol slots by corresponding correlator coefficients to correct a phase estimate of the input signal.

Abstract: A frequency signal generator includes a controller for generating a frequency generation signal, a reference frequency signal generator for generating a first frequency signal and generate a second frequency signal by dividing a first frequency signal from the controller, an assistance frequency signal generator adapted to generate a third, fourth, and fifth frequency signals and to output a sixth frequency signal in response to an assistance frequency select signal, a mixer for selecting a sign of the sixth frequency signal in response to a sign select signal and generating a seventh frequency signal and a eighth frequency signal by mixing the sixth frequency signal of the selected sign and the first frequency signal, a switch adapted to output the seventh or eighth frequency signal in response to a dividing select signal, and a first divider outputting a ninth frequency signal by dividing the eighth frequency signal from the switch.

Abstract: Radio frequency (RF) architectures for spectrum access networks are provided. Embodiments of the invention generally provide a radio frequency (RF) architecture for customer premise equipment (CPE) for use in, for example, IEEE 802.22 wireless regional area networks (WRANs). In some embodiments, the CPE RF architecture includes two receive chains with a directional antenna and an omni-directional antenna, respectively. The CPE RF architecture facilitates opportunistic out-of-band spectrum sensing and WRAN signal receiving that are performed in parallel with data transmission.

Abstract: Disclosed are hybrid heterodyne transmitters and receivers for use in communications systems, or other systems, and the corresponding methods for hybrid heterodyne transmitting and receiving. A heterodyne receiver for converting a continuous time modulated signal to a discrete time digital baseband signal includes a sigma-delta modulator. The sigma-delta modulator is a signal-delta analog-to-digital converter constructed and arranged to receive a modulated signal at an RF carrier frequency and provide a quantized output at a first intermediate frequency. The heterodyne receiver may also include a digital mixer constructed and arranged to receive a data stream quantized by the sigma-delta analog-to-digital converter and receive a signal at a second mixing frequency. The digital mixer then provides digital signals representative of a baseband signal suitable for digital signal processing.

Abstract: The radio transmitting apparatus includes a first initial phase value setting circuit that sets, in the first modulator, an initial value of the phase of the first modulated signal, which is a value at the start of the modulation according to the first modulation scheme. The radio transmitting apparatus includes a second initial phase value setting circuit that sets, in the second modulator, the phase stored in the phase storing circuit as an initial value of the phase of the second modulated signal, which is a value at the start of the modulation according to the second modulation scheme. The radio transmitting apparatus includes a signal gathering circuit that selects and outputs the first modulated signal output from the first modulator and then selects and outputs the second modulated signal output from the second modulator.

Abstract: The present invention includes a method of determining a phase estimate for an input signal having pilot symbols. The method includes receiving a plurality of pilot symbols, and then multiplying two or more pilot symbol slots by corresponding correlator coefficients to correct a phase estimate of the input signal.

Abstract: A rapidly adjustable local oscillation (LO) module for use in a radio transmitter or a radio receiver includes an oscillation generating module and a high frequency switching module. The oscillation generating module is operably coupled to generate a plurality of local oscillations. The high frequency switching module is operably coupled to, for a first one of a plurality of transmission paths, provide one of the plurality of local oscillations when a first transmission path selection indication is in a first state and provide another one of the plurality of local oscillations when the first transmission path selection indication is in a second state and, for a second one of the plurality of transmission paths, provide the one of the plurality of local oscillations when a second transmission path selection indication is in a first state and provide the another one of the plurality of local oscillations when the second transmission path selection indication is in a second state.

Abstract: A unique digital compression technology for increasing the information carrying capacity of a bandwidth limited communications path highway by using a combined coding and modulation technique. The inventive technology allows multiple independent modulated data streams to simultaneously and instantaneously share the same bandwidth without cross-channel interference. A matched filter is used to substantially reduce the error rate and utilizes a unique training method based on performing a spectral response test. An algorithm calculates the effect of the unique characteristics of the communications highway on the transmitted signal and generates an ideal signal stored in the matched filter for comparison with received signals.

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: A system and technique for providing to flexible, programmable frequency estimators and spectrum analyzers that can operate over extremely large bandwidths and yet provide high spectral resolution are described. The acquisition time and hardware complexity of one technique scale as O(N), where N denotes the number of frequency bins acquired. Embodiments are disclosed in which architectures are implemented using exponentially-tapered transmission lines and filter cascades.

Abstract: A phase-shift based pre-coding scheme used in a transmitting side and a receiving side that has less complexity than those of a space-time coding scheme, that can support various spatial multiplexing rates while maintaining the advantages of the phase-shift diversity scheme, that has less channel sensitivity than that of the pre-coding scheme, and that only requires a low capacity codebook is provided.

Abstract: There is provided a wide-band direct conversion transmitting apparatus including: a local oscillation unit generating first, second, and third oscillation signal pairs each including a pair of signals having a phase difference of 90°; an image rejection mixer unit mixing baseband transmission signals including an I signal and a Q signal having a phase difference of 90° with the first oscillation signal pair; a harmonic rejection mixer unit mixing each of the first, second, and third oscillation signal pairs with the baseband transmission signals; and an output signal selecting unit selecting output signals from the image rejection mixer unit or from the harmonic rejection mixer unit.

Abstract: A phase-shift based pre-coding scheme used in a transmitting side and a receiving side that has less complexity than those of a space-time coding scheme, that can support various spatial multiplexing rates while maintaining the advantages of the phase-shift diversity scheme, that has less channel sensitivity than that of the pre-coding scheme, and that only requires a low capacity codebook is provided.

Abstract: A method for adapting filter cut-off frequencies for the transmission of discrete multitone symbols, where a transmit symbol datastream consisting of discrete multitone symbols is applied to an interpolation device, the transmit symbol datastream is interpolated with a symbol rate in the interpolation device, an interpolated symbol datastream is filtered in a first low-pass filtering device in accordance with a first filter cut-off frequency, which can be predetermined by a first filter cut-off frequency determining device, a digital symbol datastream obtained after a digital-analog conversion, transmission and analog-digital conversion, is filtered at the receiver end in a second low-pass filtering device in accordance with a second filter cut-off frequency, which can be predetermined by a second filter cut-off frequency determining device, in order to provide an equalized symbol datastream, the equalized symbol datastream is decimated in a decimation device and the decimated received symbol datastream consi

Abstract: Improvements are disclosed for in-band signaling, i.e., transmission of data in a voice channel of a digital wireless network during a voice call session. A family of narrow-band signaling methods is disclosed to successfully pass data-carrying signals through the low-bit rate modes of the EVRC-B vocoder commonly used in CDMA wireless channels. Some embodiments generate a tapered signaling waveform in tandem with another waveform using FSK-modulation. These features can be used in cell phones or other wireless communication devices, including automotive applications.

Abstract: The invention is directed to digital generation of RF signals. In the digital domain, digital RF signals are converted to the digital signals clocked at a high speed clock that is phase-synchronized with the RF carrier. A band-pass delta-sigma modulator produces a bit stream from the converted digital signals.

Abstract: An Orthogonal Frequency Division Multiplexer (OFDM) transmitter and receiver apparatus consistent with certain embodiments of the present invention receives data to be transmitted and maps (204) a first portion of the data to a first polarization state and a second portion of the data to a second polarization state. A first transmitter (216) transmits the first portion of the data as a set of first OFDM subcarriers using an antenna (230) exhibiting a first polarization. A second transmitter (234) transmits the second portion of the data as a set of second OFDM subcarriers using an antenna (240) exhibiting a second polarization, wherein the first polarization is orthogonal to the second polarization. A receiver apparatus uses a first antenna (302) exhibiting the first polarization and a second antenna (306) exhibiting the second polarization.

Abstract: there is provided a spreading apparatus using a child orthogonal variable spreading factor (OVSF) code pair, including: a channel condition information receiving unit for receiving channel condition information including a channel condition metric; a switch controlling unit for receiving the channel condition information from the channel condition information receiving unit and transferring data stream according to the received channel station information; a first spreading unit for receiving the data stream from the switching controlling unit, and spreading the data stream using a single OVSF code; and a second spreading unit for receiving the data stream from the switching controlling unit, and spreading the data stream using a child OVSF code pair.

Abstract: A receiver operatively coupled to an antenna structure capable of receiving a first plurality of RF signals is disclosed herein. The receiver includes an RF processing network operative to perform weighting and combining operations within the RF domain using the first plurality of RF signals so as to produce a second plurality of RF signals. Also provided is a downconverter configured to downconvert the second plurality of RF signals into a second plurality of down-converted signals. In alternate implementations certain of the weighting and combining operations are performed at baseband and the remainder effected within the RF domain. A transmitter of corresponding architecture is also disclosed.

Abstract: A multi-mode PLL frequency synthesizer of a wireless multi-mode transceiver is provided which includes a reference frequency source providing an oscillator signal with a constant reference frequency, a first frequency synthesizer subunit for converting the signal into carrier signals with frequencies in the range of a first frequency band, a second frequency synthesizer subunit for transforming the oscillator signal into carrier signals having frequencies in the range of a second frequency band, and a third frequency synthesizer subunit for converting the oscillator signal into an auxiliary signal with a fixed frequency. The auxiliary signal is used together with the carrier signals of the second frequency band to generate carrier signals with frequencies in the range of a third and fourth frequency band.

Abstract: A frequency synthesizer switches the frequency at a high rate, is of low power consumption, and has a high signal-to-noise ratio. CMOS quadrature VCOs 31, 32 generate and output four-phase signals 36, 37, respectively. CMOS selector 33 selects either one of two four-phase signals 36, 37 generated by CMOS quadrature VCOs 31, 32 and outputs the selected signal as output signal 38. CMOS SSB mixer 34 multiplies output signal 38 selected by CMOS selector 33 and four-phase input signal 39 input from an external source by each other to generate a signal having a frequency represented by the sum of, or the difference between, the frequency of output signal 38 and the frequency of four-phase input signal 39, and outputs the generated signal as output signal 40. CML buffer 35 adjusts the level of output signal 40 from CMOS SSB mixer 34 and outputs the level-adjusted signal to another circuit.

Abstract: An apparatus comprising 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 (i) a modulated signal and (ii) a seed value. The second circuit may be configured to generate a first control signal in response to the demodulated signal. The third circuit may be configured to generate a second control signal in response to (i) the first control signal and (ii) a compensation signal. The fourth circuit may be configured to generate the seed value in response to the second control signal.

Abstract: The system and method enable simpler analog processing in a transmitter by reducing the number of bits in a digital signal through delta sigma modulation. Selection of current sources in a digital to analog converter of the transmitter is done using a randomization circuit.

Abstract: A correlator despreads a P/N long code constructed from two or more constituent codes A, B, C having N, M and L elements respectively. In a third stage, L filter taps decorrelate elements of the third constituent code from the input received signal, leaving elements of code AB. The outputs of the third stage delay line are summed and input into a second stage delay line having M filter taps to decorrelate the elements of the second constituent code from the input to the second stage, leaving elements of code A. The outputs of the second stage delay line are summed and input to a first stage delay line having N filter taps. The output of the first stage delay line is summed and input into a shift register. An energy peak in the shift register indicates the phase of the P/N elements in the register is proper.

Abstract: The present invention relates to an I/Q modulator using a current-mixing method used for a direct conversion wireless communication transmitter. In accordance with the present invention, an EVM of a wireless communication system, a linearity and a power consumption are improved by converting a D/A converted signal to a current level and then performing a frequency modulation.

Abstract: A method is provided for generating a multiple band ultrawide bandwidth signal. In this method, an ultrawide bandwidth devices provides a first reference signal having a first reference frequency, and a second reference signal having a second reference frequency that is different from the first reference frequency. The device generates a first ultrawide bandwidth signal based on the first reference signal, and a second ultrawide bandwidth signal based on the second reference signal, creating two separate frequency bands. These two signals can be generated form the same base clock signal, allowing for significantly simpler implementation and modification.

Abstract: Embodiments of system and method for generating common phase error (CPE) estimates in a multicarrier receiver are generally described herein. Other embodiments may be described and claimed. In some embodiments, the CPE estimates may be generated for each channel between two or more transmit antennas and the multicarrier receiver.

Abstract: Provided are a pulse signal generator for UWB radio transception and a radio transceiver having the same. The pulse signal generator includes: an envelope generator generating a plurality of envelope signals; a local oscillator array composed of a plurality of high frequency oscillators, each outputting two oscillation signals having a phase difference from each other; a multiplier array receiving the envelope signals and the oscillation signals and outputting signals obtained by respectively multiplying the envelope signals by the oscillation signals; and an I channel adder and a Q channel adder outputting an I channel pulse signal and a Q channel pulse signal by adding output signals having the same phase components among the signals output from the multiplier array, respectively.

Abstract: An up-conversion mixing system with high carrier suppression, which includes first and second LPFs to filter a first and a second input signals to thereby produce a first and a second filtered signals respectively; a first amplifier to amplify the first input signal and the first filtered signal to thereby produce a first amplified signal; a second amplifier to amplify the second input signal and the second filtered signal to thereby produce a second amplified signal, wherein the second amplifier is cross-coupled with the first amplifier in order to couple the first and the second amplified signals, thereby reducing a DC offset of a differential voltage output by the first and the second differential output terminals; and a switch to receive a differential local oscillation signal to shift the first and the second amplified signals up to frequencies associated with the local oscillation signal.

Abstract: Methodology for processing of RF signals for receiving and transmission, which varies the frequencies of local oscillators, in order to enable the receivers and transmitters to operate with higher performance in wider or multi-bands. bands. Their integrations into ICs are also made easier.

Abstract: An orthogonal modulating circuit for modulating signals of two oscillation frequencies differing in phase by 90° with transmission data (I and Q) is used in common for a plurality of bands, an LC resonance circuit comprising inductances L and a capacitor C is used as the output load on the orthogonal modulating circuit instead of resistors commonly used according to the prior art, and the values of L or C constituting the resonance circuit are switched over between each other according to the transmission band.

Abstract: A signal generator comprises at least one first base band unit and a second base band unit, generating a digital base band signal. At least one first frequency offset unit, connected to the first base band unit, which adds the output signal form the second base band unit and the output signal from the frequency offset unit and an I/Q modulator, in series with the addition unit are provided.

Abstract: A frequency generator is provided. The generator comprises two voltage controlled oscillators generating a first signal of a given multiple of a predetermined raster frequency, and a second signal of another given multiple of a predetermined raster frequency, dividers dividing the output signal of the oscillator until the frequency of both divided output signals is equal to the raster frequency, a filter arrangement connected to the output of the dividers, and a single sideband mixer. The mixer produces as output a signal having a frequency which is equal to the frequency of the output signal of either one of the oscillators or to the frequency of the output signal of either one of the oscillators from which the output signal of the filter arrangement has been subtracted or to which the output signal of the filter arrangement has been added.