Abstract: Methods and systems are described for processing a signal in wireless communications. The signal may have synchronization information. A method of processing a signal having synchronization information may include receiving the signal, and determining a truncation region of the time domain estimated channel, the estimated channel having taps. The method further includes processing the channel taps within the truncation region.

Abstract: A mobile communication device has a power amplifier and a power pack. The power pack includes a charge storage component, a first pair of taps connected to the charge storage component for supplying power to components of the mobile communication device and a second pair of taps connected to the charge storage component for supplying power to the power amplifier, the second pair of taps located, when the power is installed in the mobile communication device, more proximate to the power amplifier than the first pair of taps. With the second pair of taps positioned more proximate to the power amplifier, the power amplifier current loop that includes the multi-tap power pack may be made smaller. One benefit of a smaller power amplifier current loop may be reduced emission of RF interference signals.

Abstract: A communication device according to an embodiment of the present invention includes a communication antenna that receives a transmission signal where a spectrum spread signal subjected to a spectrum spread is modulated; an intermediate frequency converting unit that converts the transmission signal received by the communication antenna into an intermediate frequency signal having a predetermined frequency; an analog to digital converting unit that discretizes the intermediate frequency signal and outputs a discretization signal; a noise removing unit that detects a noise other than a normal thermal noise included in the discretization signal and removes the detected noise from the discretization signal; and a demodulating unit that demodulates the spectrum spread signal, based on the discretization signal that is output from the noise removing unit.

Abstract: A distortion compensation device includes a distortion compensator that predistorts an input signal based on delay signals and distortion compensation coefficients corresponding to the respective delay signals obtained by applying different amounts of delay to the input signal, a calculator that calculates an error signal based on the predistorted input signal and an output signal from an amplifier that amplifies the predistorted input signal, a calculator that calculates prospective distortion compensation coefficients for updating the distortion compensation coefficients, based on the error signal, a saturation processor that performs saturation processing for bringing, when the prospective distortion compensation coefficients do not fall into a preset range, the prospective distortion compensation coefficients into the preset range, and a controller that controls the updating of the distortion compensation coefficients based on pieces of coefficient saturation information indicating whether the saturation

Abstract: System and method for evaluating a transmitter by estimating IQ impairments in an orthogonal frequency division multiplexed (OFDM) signal generated by the transmitter. The OFDM signal may be received. The OFDM signal may represent a stream of symbols, each comprising a plurality of subcarriers. At least a subset of the subcarriers may be pilot subcarriers. The pilot subcarriers may be grouped into one or more groups of pilot subcarriers based on one or more conditions: a pilot subcarrier which satisfies a condition in its relation to a mirror subcarrier may be grouped with other pilot subcarriers which also satisfy the condition in relation to mirror subcarriers. An estimate of one or more of gain imbalance or quadrature skew of the OFDM signal may be calculated based on the one or more groups of pilot subcarriers and the one or more conditions. The estimate may be used to evaluate the transmitter.

Abstract: A communication device and method of removing an LO leakage signal from a signal path on the fly is disclosed. The signal path may be that of a transmitter or receiver. An initial RF output signal, containing a desired RF output signal and an LO leakage signal, is supplied from a feedforward path to a combiner/splitter on a feedback path. A 180° out-of-phase copy of the desired RF output signal is also supplied to the combiner/splitter. The resulting LO leakage signal is down-converted and the power of the down-converted signal determined and used to suppress the LO leakage signal. The resulting LO leakage signal is also supplied to the feedforward path of the feedback loop.

Abstract: In accordance with another representative embodiment, a high-frequency signal transmitter a power amplifier configured to supply a high-frequency signal; an antenna configured to transmit the high-frequency signal; a transmission line configured to transfer the high-frequency signal from the power amplifier to the antenna; and an impedance matching circuit connected to the transmission line. The high-frequency signal transmitter also comprises a mismatch detector.

Abstract: A transmission circuit for radio frequency signals has a power mixer and includes a radio frequency input port, a first radio frequency output port, a second radio frequency output port, and a dummy load port. The transmission circuit also has a first switch unit and a second switch unit. The first switch unit is connected to the first radio frequency output port and outputs the radio frequency signals which are emitted from the first radio frequency output port or reflects the radio frequency signals which are emitted from the first radio frequency output port back to the first radio frequency output port. The second switch unit is connected to the second radio frequency output port and outputs the radio frequency signals which are emitted from the second radio frequency output port, or reflects the radio frequency signals which are emitted from the second radio frequency output port back to the second radio frequency output port.

Abstract: A wireless device includes an antenna, Radio Frequency (RF) circuitry, and baseband processing circuitry. The baseband processing circuitry couples to the RF circuitry and is operable to determine operational calibrations settings that may include pre-distortion characteristics and RF signal path settings, both of which are determined via calibration operations. The calibration operations are initiated when an operational value of the wireless device compares unfavorably to at least one operational threshold. Monitoring circuitry coupled to the RF circuitry and to the baseband processing circuitry monitors operational characteristics of the RF circuitry. Calibration operations may be initiated based upon RF circuitry temperature, supply voltage, PA current, PA gain input level/average, among other triggers.

Abstract: Direct detection of wireless interferers in a communication device for multiple modulation types. One or more radios implemented within a communication device is/are operative to receive and process wireless communications. A wireless communication signal is processed to extract symbols there from. Various symbols groups are processed in accordance with correlation processing to identify potential interferers (e.g., other communication devices using common portions of frequency spectra). Alternatively, matched filter processing (e.g., using a Barker matched filter in some embodiments) operates on the various symbol groups to identify some potential interferers. Various combinations of correlation processing and matched filter processing may be employed in other instances (e.g., using any of a desired means of comparison, combining, etc.) in considering interferers identified in accordance with each of these two means.

Abstract: A multi-user detector (200) and method (300) for use in a cellular CDMA system (100) based on: estimating (210) spare code resource available in a first cell of the system; selecting (220) at least a second cell neighbouring the first cell; selecting (230) from codes associated with the second cell at least one additional code; and performing (240) multi-user detection processing in the first cell with the at least one additional code. On the downlink, codes from other users in the same cell may be treated with the same level of priority as those of users from neighbour cells, codes allocated to the UE having the highest priority; on the uplink, codes of all users in the same cell may have the same priority which is higher than that of neighbour cell users.

Abstract: A high frequency power amplifier maintains an excellent linearity regardless of a fluctuation of a load impedance and is downsized. The high frequency power amplifier detects an AC voltage amplitude at an output terminal of a final amplification stage transistor, and suppresses an input signal amplitude of a power amplifier when the voltage amplitude exceeds a predetermined threshold value.

Abstract: Methods and apparatus for signal and interference energy estimation in a communication system. In an aspect, a method includes setting a threshold value, and comparing a channel estimate to the threshold value to determine an interference estimate (Iest). The method also includes averaging the interference estimate (Iest) to determine average channel interference (Ic), and determining interference energy (I) based on the interference estimate (Iest) and the average channel interference (Ic). In another aspect, an apparatus includes threshold logic configured to set a threshold value and compare a channel estimate to the threshold value to determine an interference estimate (Iest). The apparatus includes averaging logic configured to average the interference estimate (Iest) to determine average channel interference (Ic), and summing logic configured to determine interference energy (I) based on the interference estimate (Iest) and average channel interference (Ic).

Abstract: The present invention relates to an apparatus and a method for measuring an in phase and quadrature (IQ) imbalance. One embodiment according to the present general inventive concept can provide a method for measuring a Tx IQ imbalance generated in an IQ up-conversion mixer and an Rx IQ imbalance generated in an IQ down-conversion mixer, that includes measuring a first IQ imbalance corresponding to a first combination of the Rx IQ imbalance with the Tx IQ imbalance, measuring a second IQ imbalance corresponding to a second combination of the Rx IQ imbalance with the Tx IQ imbalance and obtaining the Tx IQ imbalance and the Rx IQ imbalance from the first IQ imbalance and the second IQ imbalance.

Abstract: What is discloses is a method of operating a wireless access node controller, where the wireless access node controller is supporting a first communication session with a wireless communication device. The method includes transferring communications of the first communication session for delivery to the wireless communication device over a plurality of forward links, and receiving a user content message of a second communication session for delivery to the wireless communication device. The method also includes determining a weakest of the plurality of the forward links, and transferring the user content message for delivery to the wireless communication device over the weakest of the plurality of the forward links.

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: A method for deriving interference signals from modulated, digital signals is provided. The receiver end reconstructs the modulated digital signals sent by a transmitter. These reconstructed modulated digital signals are then subtracted from the received modulated digital signals, and the result of the subtraction is used to estimate the interference signals without influence by prior filtering at the receiver end. By way of example, it is possible to demodulate the interference signals estimated at the receiver end in order to ascertain possible unauthorized carrier frequencies which disturb the regular carrier frequencies, even if the interference signals are not completely in the bandwidth of the regular carrier frequency or carrier frequencies.

Abstract: A wireless communication system, a base station device, a mobile station device, and a macrodiversity selection method of the invention, in a base station device including a macrodiversity function among a plurality of sectors, select a macrodiversity method for the mobile station device from a plurality of macrodiversity methods, in accordance with a predetermined determination reference based on reception conditions of the mobile station device.

Abstract: A transmitter (106) for transmitting a signal, the signal comprising a plurality of signal values, the signal values being grouped to at least one signal value block. The transmitter comprises a pre-transformation unit (101) adapted to process each signal value block by a pre-transformation to produce a block of modulation symbols, wherein the pre-transformation comprises a phase rotation of the signal block values, which corresponds to the multiplication of the signal value block with a phase rotation matrix. The transmitter also comprises a modulation unit (102) adapted to modulate at least one carrier signal based on the modulation symbols and a sending unit (104) adapted to send the modulated carrier signal.

Abstract: The present invention relates to a method of suppressing noise in a communication device. The idea consists in forwarding to a noise suppression module some information regarding the radio transmission in terms of radio activity and/or in terms of radio transmission power. The module then advantageously uses this information to suppress radio path noise.

Abstract: A RF switch may be used as a power splitter in order to allow WLAN and Bluetooth (BT) coexistence. Multiple branches of the RF switch are enabled concurrently, which allows WLAN and BT signals to be received simultaneously. The RF switch functions as a power splitter to split signals received from an antenna to both a WLAN receiver and a BT receiver. In one embodiment, a second switch may be placed on an output of a low noise amplifier (LNA). This configuration will operate as a power splitter between WLAN receiver port and a BT port, and maximize the receiver sensitivity by amplifying both the WLAN and BT signals. One or both of the two switches may also function to bypass the LNA when the LNA is not needed to provide a low loss RF path, which serves to broaden the dynamic range of the device and avoid signal distortion during periods of increased signal power.

Abstract: Included is a radio transmission system comprising a plurality of power amplifiers (PAs); a plurality of Volterra Engine (VE) linearizers corresponding to the PAs; a plurality of feedback loops corresponding to the PAs; at least one digital hybrid matrix (DHM) coupled to the VE linearizers; and an analog hybrid matrix (AHM) coupled to the PAs, wherein the feedback loops are connected to the AHM and the VE linearizers but not to the PAs to reduce the number of feedback loops. Also included is a radio system comprising a plurality of PAs; a Volterra DHM (VDHM) coupled to the PAs; a plurality of feedback loops corresponding to the PAs; and an AHM coupled to the PAs, wherein the feedback loops are connected to the AHM but not to the PAs to reduce the number of feedback loops.

Abstract: A common resistor is connected to load impedances that convert differential currents respectively generated by current sources into differential voltages. A constant current generated by the current sources is supplied to the common resistor to cause the common resistor to generate an in-phase current and set a common potential.

Abstract: A method, an apparatus, and a computer program for performing cognitive communications in a radio environment are presented. First, a radio communication device estimates a time-varying interference environment in a radio communication channel. On the basis of the estimation, a future interference environment is predicted from time-varying characteristics of the estimated interference. Upon predicting the future interference environment, a radio transmitter is configured to apply transmission parameters to be used in a future transmission time instant for which the interference environment has been predicted. As a consequence, the transmission parameters are selected proactively to match with the predicted interference environment. The transmission parameters may be configured as time-variant.

Abstract: A filtering circuit with a jammer generator cancels a jammer in wireless signals with little degradation of the signal-to-noise ratio (SNR). The filtering circuit may include a jammer generator which acquires information of period and phase of a sinusoidal jammer signal in a composite input sinusoidal signal, which includes the jammer signal and a desired signal, and outputs a pseudo sine-wave with a period and phase corresponding with the period and phase of the jammer signal acquired, and an adder which outputs a difference between the input and output signals of the jammer generator as the desired signal.

Abstract: Aspects of a method and system for a programmable interference suppression module may include receiving a communication signal comprising one or more desired signal, and one or more undesired signals. The communication signal may be utilized to generate estimated channel state information. The estimated channel state information may be formatted for use in interference suppression. A reduced interference signal may be generated from a delayed version of said communications signal and the estimated channel state information, wherein the one or more undesired signals may be attenuated. The reduced interference signal may be formatted for post-processing. The desired signals may comprise WCDMA and/or HSDPA signals, and the undesired signals may be inter-cell and/or intra-cell interference. Further processing may comprise HSDPA processing and/or RAKE finger processing. The communication signal may be a Universal Mobile Telecommunication System (UMTS) compliant signal.

Abstract: Systems, methods, and computer readable media for fractional pre-emphasis of multi-mode interconnect are disclosed. According to one aspect, the subject matter described herein includes a method for fractional pre-emphasis of multi-mode interconnect. Multiple bits of binary data are periodically received. For each period, the multiple bits of binary data are encoded into multiple scalar values, each value representing a level of an analog signal to be output over a multi-mode interconnect system during the current period. Multiple analog signal outputs are generated corresponding to multiple scalar values, each signal output being driven to a level according to its corresponding scalar value. For each representative scalar value, a difference between the scalar value generated during the current period and the scalar value generated during the previous period is determined, and a pre-emphasis signal that is proportional to the difference is generated.

Abstract: A communications system receives a modulated signal that carries encoded communications data. An adaptive filter has a plurality of non-adaptive and adaptive filter taps with weighted coefficients and a tap order selection circuit for selecting the number and order of adaptive filter taps based on one of at least measured output power from the adaptive filter and signal modulation. A demodulator and decoder receives the filtered output signal and demodulates and decodes the signal to obtain the communications data.

Abstract: In accordance with some embodiments of the present disclosure, a method may include digitally pre-distorting a digital baseband signal with an opposite phase of a C-IM3 distortion term such that the pre-distortion and C-IM3 distortion cancel each other out in a transmitter. The method may also include digitally conditioning the pre-distorted digital signal in order to provide a flat amplitude response of a composite filter comprising a baseband filter and a digital half-band filter of the transmitter, and to provide a linear phase response for the composite filter.

Abstract: An adjustable filter is responsive to a control signal to change a frequency response of the adjustable filter based on at least one of a geographic location, frequency spectrum information, and a status of a secondary internal radio. The control signal may shift a center of the pass band from a first center frequency to a second center frequency and/or change a pass band bandwidth from a first bandwidth to a second bandwidth. A transmitter includes an adjustable filter responsive to a control signal and controller configured to select a frequency response of the adjustable filter by generating the control signal based on a geographical location. In one aspect, the geographical location indicates a region of operation of the receiver and the frequency response is selected in accordance with the region.

Abstract: This distortion compensator apparatus is a distortion compensator apparatus compensating nonlinearity of an amplifier and includes: a memory storing a compensation parameter used for correcting an input signal of the amplifier; a compensator correcting the input signal of the amplifier based on the compensation parameter; and an update controller updating the compensation parameter according to an operation state of the amplifier.

Abstract: An adjustable filter is responsive to a control signal to change a frequency response of the adjustable filter based on at least one of a geographic location, frequency spectrum information, and a status of a secondary internal radio. The control signal may shift a center of the pass band from a first center frequency to a second center frequency and/or change a pass band bandwidth from a first bandwidth to a second bandwidth. A receiver includes an adjustable filter responsive to a control signal and controller configured to select a frequency response of the adjustable filter by generating the control signal based on a geographical location. In one aspect the geographical location indicates a region of operation of the receiver and the frequency response is selected in accordance with the region.

Abstract: Architecture that enables wireless narrowband devices (e.g., wireless microphones) and white space devices to efficiently coexist on the same telecommunications channels, while not interfering with the usability of the wireless narrowband device. The architecture provides interference detection, strobe generation and detection and, power ramping and suppression (interference-free coexistence with spectrum efficiency). The architecture provides the ability of the white space device to learn about the presence of the microphone. This can be accomplished i using a geolocation database, reactively via a strober device, and/or proactively via the strober device. The strober device can be positioned close to the microphone receiver and signals the presence of a microphone to white space devices on demand.

Abstract: A wireless transmitter (100) comprises a signal generator (10) for generating a signal, an amplifier (50) for amplifying the signal, and a phase shifting circuit (20) coupled between the signal generator (10) and the amplifier (50) and arranged to shift the phase of the signal to cancel remodulation of the signal generator (10) by the amplified signal.

Abstract: An efficiency controlling module of a power amplifier for wireless communication device includes an attenuator, a filter, and a DC/DC convertor electronically connected in series. The attenuator obtains and attenuates efficiency controlling signals. The filter reduces noise in the efficiency controlling signals. The DC/DC convertor dynamically adjusts an output voltage according to the efficiency controlling signals.

Abstract: Aspects of the invention may comprise calibrating operations of wireless transmitters and/or receivers in a communication device to mitigate interference caused during concurrent communications via the wireless interfaces in the communication device. Calibration may be performed dynamically, and may comprise managing system parameters and/or physical resources of the communication device and/or the wireless transmitters and/or receivers; managing characteristics of wireless communication performed via the wireless transmitters and/or receivers; and/or managing isolation between two or more of said plurality of wireless transmitters and/or receivers in said communication device. The calibration may be performed based on data generated, via the wireless transmitters and/or receivers, during active and/or idle phases of operations. The data may be based on monitoring of RF effects caused by operations of other wireless transmitters and/or receivers.

Abstract: A digital broadcast transmitting/receiving system and a signal processing method thereof that can improve the receiving performance of the system. A digital broadcast transmitter has a randomizer to randomize an input data stream which has null bytes being inserted at a specified position, a multiplexer to output a data stream formed by inserting specified known data into the position of the null bytes of the randomized data stream, an encoder to encode the data stream outputted from the multiplexer, and a modulator/RF-converter to modulate the encoded data, RF-convert the modulated data and transmit the RF-converted data. The receiving performance of the digital broadcast transmitting/receiving system can be improved even in a multi-path channel by detecting the known data from the received signal and using the known data in synchronization and equalization in a digital broadcast receiver.

Abstract: The present invention has an object of providing a transmitter apparatus, a mobile communication system, a base station and a communication enable signal transmitter unit, which can prioritize communications of a mobile station in a priority communication system over communications of a mobile station in a non-priority communication system, in a network where the priority communication system and the non-priority communication system coexist in the same communication area.

Abstract: A system for determining allowed channels for operating in unlicensed bandwidth. Initially, an apparatus may determine whether valid allowed channel information corresponding to the current position of the apparatus already exists in the apparatus. If the allowed channel information corresponding to the current position of the apparatus does not exist in the apparatus or is invalid, the apparatus may then determine if the allowed channel information can be provided by another apparatus. If the allowed channel information is available from another apparatus, this information may be requested from the other apparatus. Otherwise, the allowed channel information may be requested from a database.

Abstract: The instant invention relates to an apparatus and method for enhancing DC offset correction speed of a radio device. On the exemplary, the apparatus includes one or two-stage signal-processing units and a controller. Each signal-processing unit has a baseband filter, a gain stage and a DC offset correction (DCOC) loop applied on the gain stage. A connection direction of an electrode terminal of a capacitor of the baseband filter is capable of being switched by the controller to process a pre-charge or a discharge phases thereby adjusting a bandwidth of the baseband filter to be either a normal operational bandwidth or wider than the normal operational bandwidth for rapidly setting time of the baseband filter.

Abstract: A method for reducing inter-cell interference and a method for transmitting a signal by a collaborative MIMO scheme, in a communication system having a multi-cell environment are disclosed. An example of a method for transmitting, by a mobile station, precoding information in a collaborative MIMO communication system includes determining a precoding matrix set including precoding matrices of one more base stations including a serving base station, based on signal strength of the serving base station, and transmitting information about the precoding matrix set to the serving base station. A mobile station in an edge of a cell performs a collaborative MIMO mode or inter-cell interference mitigation mode using the information about the precoding matrix set collaboratively with neighboring base stations.

Abstract: A method of transmitting information in a wireless communications system can be provided by selectively applying filtering to transmission of a carrier signal of a first band of frequencies of a wireless communications system based on a frequency separation distance between a frequency content of the carrier signal and a second band of frequencies allocated to a communications system other than the wireless communications system.

Abstract: There is provided a base station control apparatus and a base station control method in which a frame is segmented in a situation in which interference may occur. A BS controller divides and controls a base station into three sectors and controls communications with terminal stations (TSs). A control unit determines whether or not the TS is in at least any of a state in which the TS is interfered within a certain sector by any other sector and a state in which the TS is located in a boundary between a plurality of sectors, and segments a communication frame for a TS which is determined as being in at least any of a state in which the TS is interfered within a certain sector by any other sector and a state in which the TS is located in a boundary between a plurality of sectors.

Abstract: A transmitting unit (12) clips a communication signal (14) to form a threshold-responsive signal (36, 36?) which includes in-band distortion (40) and out-of-band distortion (38). A portion of the out-of-band distortion (38) is notched within rejection bands (48, 50) adjacent to the communication signal's bandwidth (24). But remaining portions of the out-of-band distortion (38) and portions of the in-band distortion (40) are included with the communication signal (14). The remaining portion of the out-of-band distortion (38) causes the communication signal (14) to be in violation of a spectral mask (30). The mask-violating communication signal 14 with out-of-band distortion (38) and in-band distortion (40) is amplified by an RF power amplifier (22). After amplification, a bandpass filter (92) exhibiting fast rolloff regions (110) attenuates the amplified out-of-band distortion (38) causing compliance with the spectral mask (30).

Abstract: It is possible to restrain distortions generated in a mixer. A modulator includes a local signal source that generates an in-phase local signal, a multiplier that multiplies an in-phase baseband signal (I) and the in-phase local signal by each other, a phase inverter that receives the in-phase local signal from the local signal source, and inverts the phase thereof, an anti-phase multiplier that multiplies an anti-phase baseband signal (?I) (signal equivalent to a signal obtained by inverting the phase of the in-phase baseband signal (I)) and an output from the phase inverter (anti-phase local signal) by each other, and an adder that adds an output from the multiplier and an output from the anti-phase multiplier to each other. The addition by the adder of a leak component (carrier leak) which is the in-phase local signal leaked from the multiplier, and the signal which is the output from the phase inverter leaked from the anti-phase multiplier to each other results in zero.

Abstract: A system includes an antenna to receive a communications signal, an amplifier coupled to the antenna to amplify the communications signal, and a processor coupled to the amplifier to process the communications signal using high-order statistics to suppress noise in the communications signal. The processor may use a bispectrum function to remove at least a portion of the noise, and at least one of the phase of the bispectrum and the amplitude of the bispectrum to reconstruct the communications signal.

Abstract: A base station (BS), a subordinated station (SS) and the transmission methods thereof for use in a multi-input multi-output (MIMO) network are provided. The BS stores resource allocation information about the MIMO network and an SS list, and generate a super frame according to the resource allocation information and the SS list. The super frame comprises a pilot pattern which comprises a plurality of pilots and data. The BS and SS both considers the pilot pattern as an identifier of the SS. When there are communications occurred between the BS and the SS, the BS/SS will confirm whether the pilot pattern of the super frame matches the identifier of the SS to reduce interference from other stations in the MIMO network.

Abstract: A wireless communication device that includes a wireless communication unit that performs a wireless communication in a first mode using a first frequency band serving as a first communication channel, and performs the wireless communication in a second mode using a second frequency band including the first communication channel and a second communication channel that is adjacent to the first communication channel. Also included is a detection unit that monitors each of the first frequency band and the second frequency band, outputs a first detection signal when an interference signal is detected in the first frequency band and outputs a second detection signal when the interference signal is detected in the second frequency band. Further included is a determination unit that determines whether the interference signal is in the first communication channel or in the second communication channel based on the first and second detection signals.

Abstract: Elimination of intermodulation interference in a wireless communication system by removing a portion of the spectrum of transmitted signals. According to a received indication of an occurrence of intermodulation interference experienced by a narrowband receiver, mappings are performed between the predetermined narrowband channel frequency on which the narrowband receiver operates and the occupied channel frequencies of at least one broadband transmit signal. Narrowband candidate frequency ranges that linearly combine into frequencies that overlap the predetermined narrowband channel frequency are determined based on the mappings. The narrowband candidate frequency ranges that potentially contribute to the intermodulation interference are then selectively filtered by at least one notch filter until the intermodulation interference is substantially eliminated.

Abstract: A technique is used to realize a generalized decision feedback equalizer (GDFE) Precoder for multi-user multiple-input multiple-output (MU-MIMO) systems, which significantly reduces the computational cost while resulting in no capacity loss. The technique is suitable for improving the performance of various MU-MIMO wireless systems including future 4G cellular networks. In one embodiment, a method for configuring a GDFE precoder in a base station of a MU-MIMO wireless system having k user terminals, each user terminal having associated therewith a feedforward filter. The method comprises computing a filter matrix C using one of a plurality of alternative formulas of the invention; and, based on the computation of the filter matrix C, computing a transmit filter matrix B for a transmit filter used to process a symbol vector obtained after a decision feedback equalizing stage of the GDFE precoder, a feedforward filter matrix F, and an interference pre-cancellation matrix G.