Abstract: A method, apparatus and computer program product are configured to provide calibration accuracy in an analog filter. In this regard, a method is provided that includes estimating a cutoff frequency for an analog filter. The method further includes causing a filter tuning word to be modified based on the estimated cutoff frequency for the analog filter. The method also includes determining a residual cutoff frequency mismatch for the analog filter. The method also includes causing an equalizer configuration to be selected for a digital filter based on the determined residual cutoff frequency mismatch.

Abstract: A transmitter, channel coder, and method for coding and transmitting a sequence of symbols in a digital communication system utilizing soft pilot symbols. In one embodiment, the transmitter transmits a set of soft pilot symbols with higher reliability than the remaining symbols in the sequence by modulating the soft pilot symbols with a lower order modulation such as BPSK or QPSK while modulating the remaining symbols with a higher order modulation such as 16 QAM or 64 QAM. The transmitter shares the modulation type and location (time/frequency/code) of the soft pilot symbols with a receiver. Unlike traditional fixed pilots, the soft pilots still carry some data. Additionally, the soft pilots are particularly helpful in establishing the amplitude reference essential in demodulating the higher order modulation symbols. In another embodiment, soft pilot symbols are inserted by low-level puncturing of channel encoded bits and replacing the punctured bits with known bit patterns.

Abstract: White space signals are differentiated from licensed ATSC signals through modification of a waveform of the white space signal. White space signals may be modified by shifting the ATSC-compatible waveform so that the pilot frequency of the white space signal is at a location outside of the frequency range associated with the pilot frequency in a licensed ATSC signal or embedding a watermark signal into said ATSC-like white space signals. White space device transmitters generate the signals with these modifications and white space receivers are equipped to detect whether a pilot exists in the standard licensed pilot frequencies. Based on these differences, white space devices can better operate without interfering with licensed ATSC transmission. Additionally, the modification techniques may be used to embed data in the white space signal that may be used to communicate connection data or networking data to other white space devices.

Abstract: A receiver including a mixer configured to generate (i) a first output and (ii) a second output, a first capacitance coupled to the first output, and a second capacitance coupled to the second output, A controller is configured to program (i) the first capacitance and (ii) the second capacitance to a first capacitance value in response to operating the receiver in a first mode, and program (i) the first capacitance and (ii) the second capacitance to a second capacitance value in response to operating the receiver in a second mode. The first capacitance value determines one or more of (i) linearity, (ii) gain, and (iii) noise figure of the receiver in the first mode. The second capacitance value determines one or more of (i) linearity, (ii) gain, and (iii) noise figure of the receiver in the second mode.

Abstract: A receiving apparatus includes: a transmission path characteristics estimating section obtaining pre-interpolation transmission path characteristic data as estimate values for transmission path characteristics as characteristics of a transmission path of an OFDM signal for transmission symbols of pilot signals by using the pilot signals contained in the OFDM signal, and filtering the pre-interpolation transmission path characteristic data by using an interpolation filter, thereby obtaining transmission path characteristic data as estimate values for transmission path characteristics for transmission symbols of the OFDM signal; a distortion correcting section performing distortion correction for the OFDM signal by using the transmission path characteristic data; and a filter controlling section controlling a pass band of the interpolation filter.

Abstract: An objective is to provide a digital receiver and a method of compensating waveform that are capable of compensating waveform distortion without increasing the circuit size. A digital receiver 100 according to the present invention includes distortion compensation filters 103 that compensate waveform distortion included in an input signal, skew compensation amount setting units 106 for setting a skew compensation amount used for compensating phase distortion among the waveform distortion, amplitude compensation amount setting units 107 for setting an amplitude compensation amount used for compensating amplitude of the input signal that attenuates upon the compensation of the phase distortion using the skew compensation amount, and filter coefficient calculation circuits 108 for determining a filter coefficient to be set to the distortion compensation filters 103 based on the skew compensation amount and the amplitude compensation amount.

Abstract: Techniques for obtaining smoothed channel response estimates in a communications receiver. An example method begins with obtaining ordered channel measurement samples for a current estimation interval and continues with the estimation of a short-term slope value for each of several sequential observation time intervals. A distortion metric is calculated for each of a plurality of candidate filter lengths, where each candidate filter length is an integer multiple of the uniform length. The distortion metric is based on the short-term slope values for observation time intervals falling within the candidate filter length, and characterizes the extent to which the candidate filter length will introduce tracking bias in subsequent signal processing. A filter length is then selected for use in demodulating a received signal from at least among the candidate filter lengths, based on the distortion metric values.

Abstract: A system for and method of removing one or more unwanted inband signals from a received communications signal is described. The inband signal or signals may comprise noise, interference signals, or any other unwanted signals that impact the quality of the underlying communications. A receiver receives a communication signal, the received communication signal including the desired communication signal and one or more inband signals. A signal separator processes the received signal to form an estimate of the desired communication signal and an estimate of the inband signals. A performance improver processes the received signal and the estimate of the one or more inband signals to form an improved estimate of the desired communication signal and an improved estimate of the inband signals.

Abstract: A method of detecting a desired signal within a composite signal provides for suppression of interfering signal(s). The method, implemented in a wireless communication apparatus, for example, includes receiving the composite signal and obtaining sample values therefrom. At least some of the sample values include desired and interfering signal components. The method further includes generating an interfering signal channel estimate by: forming sample pairs for some or all of the sample values; identifying sample pairs of interest as those sample pairs in which the interfering signal component is the same; and calculating the interfering signal channel estimate as an average value determined from one or more of the sample pairs of interest. The method further includes detecting desired signal symbols from the composite signal in a joint detection process that functionally depends on the interfering signal channel estimate.

Abstract: A signal receiver is arranged to process a portion of a received signal in each of a plurality of filter branches and to determine a quality metric for each branch. The configuration of a second filter for processing the entirety of the received signal is subsequently performed according to the determined quality metrics.

Abstract: Described embodiments receive a signal by a set of fixed taps and a set of floating taps of a receiver, each tap corresponding to a detected symbol. Each of the floating taps is stored in a corresponding shift register to account for process, operating voltage and temperature (PVT) variations of the receiver without calibration of delay elements. Multiplexing logic selects (i) corresponding floating taps for equalization by coupling selected floating taps to the outputs of the fixed taps, and (ii) different phases of each possible floating tap position. The multiplexing logic prunes and/or amalgamates the phases of each possible floating tap position and selects floating taps based on a magnitude of each phase. A combiner adjusts each output value of the fixed taps and the selected floating taps by a corresponding tap-weight, combines the adjusted values into an output signal and subtracts the output signal from the input signal.

Abstract: The invention relates to an infrared receiver circuit for receiving a carrier-modulated infrared signal that comprises a carrier signal and a wanted signal modulated onto the carrier signal, having a band pass filter that exhibits a frequency adjustment connection via which the band center frequency of the band pass filter can be adjusted, furthermore having a demodulator for recovering the wanted signal and having a signal output to which the demodulated wanted signal can be output. The infrared receiver circuit exhibits a signal input that is at least indirectly connected to the frequency adjustment connection of the band pass filter so that the band center frequency of the band pass filter can be adjusted by a clock signal of an external clock pulse generator.

Abstract: Systems, methods, and other embodiments associated with adaptively determining settings of a transmit equalizer are described. According to one embodiment, a signal is received from a transmitter and a signal contribution of the transmit equalizer is removed from the signal to produce a residual signal. Revised tap coefficients are computed based, at least in part, on the residual signal. Revised tap coefficient settings, that are based, at least in part, on the revised tap coefficients, are provided to the transmit equalizer.

Abstract: Techniques for obtaining smoothed channel response estimates in a communications receiver. An example method begins with obtaining ordered channel measurement samples for a current estimation interval and continues with the estimation of a short-term slope value for each of several sequential observation time intervals. A distortion metric is calculated for each of a plurality of candidate filter lengths, where each candidate filter length is an integer multiple of the uniform length. The distortion metric is based on the short-term slope values for observation time intervals falling within the candidate filter length, and characterizes the extent to which the candidate filter length will introduce tracking bias in subsequent signal processing. A filter length is then selected for use in demodulating a received signal from at least among the candidate filter lengths, based on the distortion metric values.

Abstract: A communication system having a receiver with a linear path and a nonlinear path. As the receiver receives a data signal, it adaptively equalizes the received signal, and amplitude-limits the equalized signal in the nonlinear path using a saturable amplifier limiter or the like. A slicer extracts data from the limited equalized received signal. In the linear path, a clock recovery circuit generates a clock signal from the equalized received signal. A delay circuit in the linear path at least partially compensates for propagation delay in the limiter. Having the clock recovery occur in other than the nonlinear path, a low jitter clock is generated. The limiter enhances the vertical opening of the data eye by increasing the rise and fall times of the limited signal, providing more noise margin for the slicer to operate with and a greater timing margin in which to sample the sliced data.

Abstract: Techniques for directly adapting the parameters of a smoothing filter used for channel estimation to the current velocity and signal-to-noise ratio (SNR) situation. An example method begins with a plurality of channel response measurements. For each of a first subset of a set of pre-determined filter responses, the channel measurement samples are filtered to obtain a corresponding set of estimated channel response samples. Next, for each set of estimated channel response samples, a corresponding set of ordered residuals are calculated from the channel measurement samples. Each set of ordered residuals is evaluated to determine a measure of correlation among the ordered residuals, and an updated filter response is selected from a second subset of the set of pre-determined filter responses, based on this evaluation, for use in demodulating a received signal.

Abstract: Embodiments herein include a method of channel estimation in a wireless communication node. The method comprises generating, based on samples of a received signal, initial estimates of a plurality of channel coefficients forming a channel response. The method also entails, for each of the channel coefficients, dynamically calculating a coefficient-specific filter span for that channel coefficient. Notably, the coefficient-specific filter span for any given channel coefficient is calculated according to a closed-form function that minimizes aggregated estimation noise for the channel coefficient and estimation bias attributable to errors in tracking the channel coefficient. The method finally includes adapting filtering of the initial estimates independently for each of the channel coefficients to be performed over the coefficient-specific filter span calculated for that channel coefficient.

Abstract: A SAW-less receiver includes an interface, an RF to IF receiver section, and a receiver IF to baseband section. The RF to IF receiver section includes a frequency translated bandpass filter (FTBPF), a Low Noise Amplifier (LNA), and a mixing section. The FTBPF includes a switching network and a plurality of baseband impedances. The switching network is operable to couple the plurality of baseband impedances to the interface in accordance with a plurality of phase-offset RF clock signals to RF bandpass filter the inbound RF signal. The LNA amplifies the filtered inbound RF signal and the mixing section mixes the amplified inbound RF signal with a local oscillation to produce an inbound IF signal. The receiver IF to baseband section converts the inbound IF signal into one or more inbound symbol streams. Filtering may be prior or after amplification by the LNA.

Abstract: By exploiting the multi-block structure of the used slot format having a training sequence in the time domain and at least one pre-coded user data block to sequentially reconstruct the slot, using in the first act known symbols and using detected symbols in each subsequent act and improved receiver may be provided. This may result in less ISI/IBI and therefore increased performance.

Abstract: In addition, to pilot tones which may be existent within an orthogonal frequency division multiplexing (OFDM) signal, one or more data tones within that same signal may be employed to assist with channel estimation (alternatively, detection). Once a data tone qualifies as a pseudo-pilot tone, it may be used with the pilot tones for channel estimation. A qualifier considers slicer error associated with hard decisions for a data tone to determine if it is a candidate for assistance within channel estimation. A frame within an OFDM signal may, in one situation, include no pilot tones at all, and a previously calculated channel estimate may be used to process that frame. In addition, fewer pilot tones than needed to perform accurate channel estimation (based on the channel delay spread) may be employed by using one or more pseudo-pilot tones (e.g., qualified data tones).

Abstract: A method and apparatus is provided for reducing interference in a communication system. A feedback-controlled biased inverting limiter is used to reduce interference power by trapping the interfering signal, while passing the wanted signal through to the output. The amplitude trap triples the frequency of a signal component of a particular amplitude, thus shifting it out of the communication band and into the stopband of the receiver or transponder filter. The feedback-controlled biased inverting limiter uses a hard limiter, window comparator, feedback loop, and an exclusive NOR gate to trap the interfering signal, while allowing the wanted signal to pass through to a receiver.

Abstract: A method for jam setting an initial frequency of a data clock recovery loop according to one embodiment includes generating a frequency error signal in a frequency error detector from sideband signals within a backscattered radio frequency signal, wherein the frequency error accumulates in a frequency error filter coupled to an output of the frequency error detector; at about an end of an acquisition period, freezing the accumulated frequency error in the frequency error filter; and using the frozen accumulated frequency error to jam set an initial frequency of a data clock recovery loop. Such methodology may also be implemented as a system using logic for performing the various operations. Additional systems and methods are also presented.

Abstract: A filter includes, in at least one aspect, one or more differential inputs to receive one or more differential input signals, a first filter stage to provide one or more primary poles corresponding to a first frequency associated with the one or more differential input signals, a second filter stage coupled with the first filter stage to provide one or more secondary poles corresponding to a second frequency associated with the one or more differential input signals, the second frequency and the first frequency having a predefined relationship, and one or more differential outputs coupled with the second filter stage to provide one or more differential output signals.

Abstract: A demultiplexing device that includes frequency-conversion and reception low-pass-filter units that perform a frequency converting process and a low-pass filtering process for causing a signal to pass through a desired band, perform downsampling to reduce a sampling rate to half of a data rate of an input signal, and output the signal, reception channel-filter units that waveform-shape a signal with a desired frequency characteristic and output the waveform-shaped signal. The demultiplexing device also includes a filter-bank control unit that generates a clock control signal for supplying a clock to frequency-conversion and reception low-pass-filter units and reception channel-filter units corresponding to signal passage bands, based on channel information, and a reception-clock supply unit that supplies a clock to frequency-conversion and reception low-pass-filter units and reception channel-filter units corresponding to signal passage bands, based on the clock control signal.

Abstract: A system including a first filter module and a second filter module. The first filter module is configured to (i) pass a first DC shift in an input signal and (ii) convert a second DC shift in the input signal to a first component and a second component. The first DC shift is shorter in duration than the second DC shift. The second filter module is configured to detect one or more of (i) the first DC shift and (ii) the first component and the second component of the second DC shift. In response to detecting one or more of (i) the first DC shift and (ii) the first component and the second component of the second DC shift, the second filter module is configured to filter one or more of (i) the first DC shift and (ii) the first component and the second component of the second DC shift.

Abstract: A system that incorporates teachings of the subject disclosure may include, for example, a method for identifying a spectral region in a radio frequency spectrum for initiating a communication session having a transmission link and a reception link, determining a correlation factor from signals measured in the spectral region, detecting according to the correlation factor a foreign communication signal in the spectral region, generating coefficient data to prevent interference with the foreign communication signal while transmitting in the transmission link, filtering a first signal for transmission in the transmission link according to the coefficient data to generate a filtered signal, and causing a transmission of the filtered signal which prevents interference with the foreign communication signal while transmitting in the transmission link. Other embodiments are disclosed.

Abstract: A method for a single radio aggregated spectrum receiver of a terminal arranged to operate in a radio network is disclosed. The method comprises receiving information from a network node of the radio network about frequency properties of an aggregated spectrum to be received; determining information about the aggregated spectrum comprising at least one of presence of blocking interferer(s) interspersed with, and pass bands within the aggregated spectrum; and providing filter(s) based on the determined information about the aggregated spectrum such that desired signals are passed and any blocking interferer(s) are attenuated. Corresponding computer program, receiver and terminal are also disclosed.

Abstract: Certain aspects of the present disclosure relate to a method for equalizing a pulse signal corrupted by a noise and by various channel effects for obtaining a signal based on the periodic-sinc pulse, which is suitable for Finite Rate of Innovation (FRI) processing applied at a receiver of a pulse-based communication system (e.g., an Ultra-Wideband receiver).

Abstract: The present invention discloses a method and apparatus for wide dynamic range phase conversion. In one embodiment, inphase and quadrature signal components of a complex input signal are collapsed into a single quadrant to produce a first signal representation. A scaling operation is subsequently performed on the first signal representation to produce a second signal representation. Lastly, the second signal representation is converted into the phase domain.

Abstract: An apparatus and a method for interference cancellation in a Multiple Input Multiple Output (MIMO) wireless communication system. The method for interference cancellation includes equalizing first reception signals received through two or more reception antennas to estimate transmission signals transmitted through two or more transmission antennas, generating two or more second reception signals in which a mutual interference between the transmission signals is removed from the first reception signals by using the estimated transmission signals, independently equalizing the generated two or more second reception signals, and combining the independently equalized two or more second reception signals to estimate a transmission signal in which an interference is removed.

Abstract: The present disclosure provides methods and apparatuses for demodulating discrete-time desired signals in a period-Td bandpass desired signal in the presence of interference that results from a period-T bandpass interference signal that has been nonlinear distorted. Estimation of the nonlinear-distorted interference and subsequent cancellation from a received signal, that includes the interference and desired signal, produces residual-interference signals. The demodulation of the residual-interference signals uses an equalization technique when Td is not equal to T. The estimation, cancellation, and demodulation are adapted for changing nonlinear distortion effects.

Abstract: Apparatus and methods are disclosed, such as those involving a receiver device. One such apparatus includes an equalizer configured to process an input signal transmitted over a channel. The equalizer includes a first node configured to receive the input signal; a second node; and a programmable gain amplifier (PGA) having an adjustable gain. The PGA has an input electrically coupled to the first node, and an output electrically coupled to a third node. The equalizer also includes a high pass filter (HPF) having an input electrically coupled to the third node, and an output electrically coupled to the second node; and a control block configured to adjust one or more of the PGA or the HPF at least partly in response to a PGA output signal from the PGA or an HPF output signal from the HPF.

Abstract: Aspects of the present disclosure describe an efficient channel estimation algorithm for high-speed processing of dedicated reference signals. The channel estimation algorithm may utilize one or more compressed interpolation matrices. The compressed interpolation matrices may be selected based on the Doppler value and signal to noise ratio (SNR) of the channel.

Abstract: Multi-antenna transmission control presented herein involves generating a set of virtual channel realizations at the transmitter that shares the same second-order statistics as the actual channel realizations observed for a targeted receiver. By making the control-related quantities of interest at the transmitter depend on the long-term statistics of the channel, the actual channel realizations are not needed for transmission control, e.g., for accurate Multiple-Input-Multiple-Output (MIMO) preceding. As such, the use of virtual channel realizations enables transmission control that approaches the “closed-loop” channel capacity that would be provided by full feedback of the (instantaneous) actual channel realizations, without requiring the overhead signaling burden that attends full feedback.

Abstract: Certain aspects provide a method for determining decoding order and reconstruction weights for decoded streams to be cancelled in a MIMO system with successive interference cancellation, based on estimates of the channel characteristics, the received composite signal and parameters of the system.

Abstract: A wideband multi-channel receiver comprises an antenna configured to receive a radio frequency band comprising an aviation VHF communication band, an aviation VHF navigation band, an aviation L-band, or combinations thereof. A band-pass filter is in signal communication with the antenna, and a low-noise amplifier is in signal communication with the band-pass filter. A mixer is in signal communication with the low-noise amplifier and is configured to translate a radio frequency band to an intermediate frequency (IF) band. A tunable local oscillator is in signal communication with the mixer. At least one fixed-frequency notch filter is in signal communication with the mixer, with the notch filter configured to reject at least one interference signal in the IF band while passing remaining signals in the IF band. An analog-to-digital converter is in signal communication with the notch filter and is configured to convert the remaining signals in the IF band to digital signals.

Abstract: In a method for decoding plurality of information streams corresponding to a plurality of layers, where the plurality of information streams have been transmitted via a multiple input multiple output (MIMO) communication channel, a plurality of received signals are processed to decode information corresponding to a first layer. A plurality of modified received signals are generated using the decoded information corresponding to the first layer and the plurality of received signals. Bit metric values are generated for a second layer using MIMO maximum likelihood (ML) demodulation and using the plurality of modified received signals and channel and modulation information for interfering signals. Information corresponding to the second layer is decoded using the generated bit metric values.

Abstract: An adaptive known signal canceller comprising of a known signal canceller filter responsive to a known signal including a known portion of a transmitted signal, the known signal canceller filter operative to generate a filtered known signal, and a subtractor unit responsive to an input signal and operative to generate an output signal, the subtractor unit configured to subtract the filtered known signal from the input signal to generate an output signal, such that the known portion of the transmitted signal is substantially removed from the input signal. The adaptive known signal canceller further comprising of a known signal canceller update unit, responsive to a desired signal and an output signal and operative to continually adjust the coefficients of the known signal canceller filter based on the difference between the output signal and the desired signal, so that the filter coefficients substantially reflect the impulse response of a channel.

Abstract: A method for processing user symbols with Tomlinson Harashima precoder (THP) in a base station, of a wireless system having K user terminals (UEs) which communicate with the base station via an uplink channel and a corresponding downlink (DL) channel, comprises estimating DL channel matrix; determining receiver processing matrix; computing effective matrix DL channel Heff; performing QR decomposition of Heff; computing THP matrices; calculating scalar weights for the UEs; processing user symbols by the THP having the THP matrices to produce an output of filtered vector symbols for the UEs; directing output of the THP to a channel represented by the DL channel matrix through which communications occur in the wireless system with the UEs; providing the receiver processing matrix to the UEs for performing additional receiver processing on the transmitted signals; and providing the scalar weights to the UEs to be used on the transmitted signals at the UEs.

Abstract: A communication system is provided that includes a composite transfer module that receives an input signal and performs one or more selective operations defined by a first transfer function on the input signal. The composite transfer module outputs a first signal. A joint detection module receives the first signal and performs joint detection on the first signal. The joint detection module utilizes channel estimation information of the first transfer function so as to allow the joint detection module to perform joint detection with an oversampling rate of 2× or higher.

Abstract: One embodiment of the present invention relates to a communication system having a digital to analog converter, a first input, a summation component, a compensation filter, and a compensation unit. The converter is configured to receive a first signal. The first input is configured to receive a phase modulation signal. The compensation filter generates a filtered frequency deviation signal to mitigate frequency distortions, such as those from a digital controlled oscillator. The compensation unit includes one or more inputs and is configured to generate a correction signal according to the filtered frequency deviation signal and the first signal. The correction signal at least partially accounts for estimated distortions of the phase modulation signal from the amplitude modulation path and mitigates frequency induced distortions. The summation component is configured to receive the phase modulation signal and the correction signal and to generate a corrected phase modulation signal as a result.

Abstract: A digital signal processing circuit includes a combining stage and an output stage. The combining stage is arranged to receive a plurality of non-overlapping clock signals having a same frequency but different phases, receive a plurality of first input bit streams, and generate a first output bit stream by combining the first input bit streams according to the non-overlapping clock signals. The output stage is arranged to generate an output according to the first output bit stream. A digital signal processing method includes: receiving a plurality of non-overlapping clock signals having a same frequency but different phases; receiving a plurality of first input bit streams; generating a first output bit stream by combining the first input bit streams according to the non-overlapping clock signals; and generating an output according to the first output bit stream.

Abstract: An RF signal reception device including: a transposition device of signals of frequency fRF to a first intermediate frequency IF1<fRF; a first bandpass filter centered on IF1; a sampler at a frequency fs<IF1; a second discrete-time filter centered on a second intermediate frequency IF2=?·fs/M+fs/(M·n); a decimation device of a factor M; an analog-digital convertor to operate at a frequency fs/M; where ?, n and M are strictly positive real numbers chosen such that: ?<fs/(2·BWch·M), and BWch/2<fs/M·n), with BWch: bandwidth of a channel of the received RF signals.

Abstract: A coordinated multipoint OFDM system comprising a plurality of receiving base stations, each comprising a plurality of antennas, is described. Each base station determines and forwards interferences for each received symbol and passes the information to a central processing entity for jointly processing the signals.

Abstract: A method of frequency-domain filtering is provided that includes a plurality of filters, the plurality of filters including at least one constrained filter(s) W=I, I and at least one unconstrained filter(s) W=1, K? The method includes cascading the W k=i, K unconstrained filter(s). A single constraint window C is applied to the cascaded W=i, K unconstrained filter(s). The W=1, I constrained filter(s) are cascaded with the constrained cascaded Wk=1, K unconstrained filter(s) to form a resulting filter Wll=C(W 1{circle around (x)} . . . {circle around (x)} W) {circle around (x)} W . . . W. The frequency domain representation of the single constraint window C may be based, at least in part, on a time domain representation of a single constraint window C that has been circularly shifted such that the frequency domain representation of the constraint window matches a property of the frequency domain representation of the cascaded W=1, K unconstrained filters.

Abstract: Systems and methods for measuring transmitter and/or receiver I/Q impairments are disclosed, including iterative methods for measuring transmitter I/Q impairments using shared local oscillators, iterative methods for measuring transmitter I/Q impairments using intentionally-offset local oscillators, and methods for measuring receiver I/Q impairments. Also disclosed are methods for computing I/Q impairments from a sampled complex signal, methods for computing DC properties of a signal path between the transmitter and receiver, and methods for transforming I/Q impairments through a linear system.

Abstract: An integrated circuit comprises channel estimation module for generating at least one channel estimation signal based on at least one of a plurality of pilot signals within concurrent resource elements. The channel estimation module comprising extension module arranged to receive a demodulation reference signal comprises the plurality of pilot signals and to add an extension to the demodulation reference signal, inverse discrete Fourier transform (IDFT) module arranged to perform an inverse discrete Fourier transform function on the extended demodulation reference signal to generate a time domain reference signal, reference signal separation module arranged to separate out at least one pilot signal component from the time domain reference signal. The channel estimation module further comprises and discrete Fourier transform (DFT) module arranged to perform a discrete Fourier transform function on the at least one pilot signal component to generate at least one extended channel estimation signal.

Abstract: Techniques are described herein that receive communications transmitted according to different operation modes at a multi-mode, programmable receiver system. The multi-mode, programmable receiver system may receive communication signals from transmit antennas in “cells” (e.g., base station transceivers and/or the like) according to one or more operation modes, using receive antennas. The received signals may be converted and processed by various modules of the multi-mode, programmable receiver system to produce an output signal. The multi-mode, programmable receiver system includes modules that are programmable to be selectively enabled or disabled according to an operation mode in accordance with which the multi-mode, programmable receiver system operates.

Abstract: The described aspects include a user equipment (UE) apparatus and corresponding method of equalizing samples of received signals in wireless communication. A plurality of samples of a signal received in wireless communication can be obtained, and on-time samples and late samples of the plurality of samples are independently equalized to respectively generate equalized on-time samples and equalized late samples. In addition, a preference factor can be applied to at least the equalized on-time samples to generate preferred equalized on-time samples, which are combined with the equalized late samples to generate a set of equalized samples for decoding.

Abstract: Method for optimizing the delay spread performance of a radio receiver (200) includes evaluating (306) a delay spread environment to determine if a desired RF signal is being received under conditions of low delay spread or high delay spread. If a low delay spread condition, the baseband digital data signal is filtered using a narrow filter (310). Otherwise, the signal is filtered using a wide bandwidth filter (312) having a bandwidth wider than the narrow filter. The center frequency of the wide bandwidth filter is selectively shifted (316, 320) in accordance with a predetermined frequency offset if a second received power level of an interfering signal in an adjacent channel exceeds the first received power level by a predetermined threshold amount. This frequency shift of the filter allows for improved delay spread performance while minimizing any performance degradation when an interfering signal is present on an adjacent channel.