Abstract: A method for providing correction values for phase based measurements. Where averaging techniques are employed for exploiting redundancy in multiple measurements, by constraining the phase ambiguity in a correction value to be an integer multiple of the carrier wavelength, carrier phase based measurements can be used.

Abstract: A method of operating a Rake receiver circuit includes determining a first property of a first signal received over a dedicated channel and over a first transmission path. The method further includes determining a delay profile of a second signal and determining, on the basis of the delay profile and the first property, if the first transmission path is to be assigned to a Rake finger of the Rake receiver circuit.

Abstract: This invention teaches to the details of an interference suppressing receiver for suppressing intra-cell and inter-cell interference in coded, multiple-access, spread spectrum transmissions that propagate through frequency selective communication channels to a multiplicity of receive antennas. The receiver is designed or adapted through the repeated use of symbol-estimate weighting, subtractive suppression with a stabilizing step-size, and mixed-decision symbol estimates. Receiver embodiments may be designed, adapted, and implemented explicitly in software or programmed hardware, or implicitly in standard RAKE-based hardware either within the RAKE (i.e., at the finger level) or outside the RAKE (i.e., at the user or subchannel symbol level). Embodiments may be employed in user equipment on the forward link or in a base station on the reverse link. It may be adapted to general signal processing applications where a signal is to be extracted from interference.

Abstract: A reception device which communicates with a transmission device including multiple transmission antennas, the reception device including: at least one reception antenna which receives multiple transmission signals transmitted by the transmission device from the multiple transmission antennas; a propagation channel response estimation unit which estimates propagation channel responses among the multiple transmission antennas and the reception antenna; a block division unit which divides a reception signal of at least one of the reception antennas into multiple blocks based on a multipath; and a transmission signal detection unit which detects the transmission signals transmitted by the transmission device based on the reception signal divided by the block division unit into the multiple blocks and the propagation channel responses estimated by the propagation channel response estimation unit. The transmission signal detection unit includes: an interference cancellation unit and a signal separation unit.

Abstract: A multi-carrier linear equalization receiver, e.g., a RAKE receiver or chip equalization receiver, is described herein. The multi-carrier receiver distributes processing delays among a plurality of received carriers based on a comparison between the signal-to-interference ratios (SIRs) determined for each carrier. The receiver initially allocates a minimum number of processing delays to each carrier. In one embodiment, any remaining additional processing delays are distributed evenly between the carriers when a comparison between the largest and smallest SIR is less than or equal to a threshold. In another embodiment, the remaining additional processing delays are distributed to favor the carrier(s) with the strongest SIR(s) when the comparison between the largest and smallest SIR exceeds the threshold.

Abstract: Apparatus for determining a location of a peak in correlation output samples, the apparatus being arranged to receive samples from at least one correlator over a plurality of symbol time periods; combine samples from a period that is longer than the symbol time period into combined samples; and determine the position of a peak in the combined samples.

Abstract: An SIR estimate of a communication signal in a wireless communication system receiver is calculated based on soft bit values output by a nonlinear detector. The average amplitude of the detector output soft bits is estimated. The average power of the detector output soft bits is estimated, e.g., as a mean-square or variance. An SIR of the communication signal is estimated based on the soft bit amplitude and power estimates. In particular, the SIR is estimated as the ratio of the square of soft bit amplitude to the difference between the mean square soft bit power and the square of soft bit amplitude, or the ratio of the square of soft bit amplitude to the variance. In either case, the SIR estimate may be scaled to obtain the desired units. The communication signal may be a received signal, or a simulated signal generated using channel estimates obtained from, e.g., a pilot channel.

Abstract: A method and system for interference cancellation (IC). One aspect relates to traffic interference cancellation. Another aspect relates to joint IC for pilot, overhead and data. Another aspect relates to improved channel estimation. Another aspect relates to adaptation of transmit subchannel gains.

Abstract: Techniques for deriving channel estimates with different channel estimation filters are described. In one scheme, a filter selection metric is determined for a signal to be recovered, a channel estimation filter is selected based on the filter selection metric, and a channel estimate is derived with the selected channel estimation filter. In another scheme, a first channel estimate is derived with a first channel estimation filter having a first filter response, a first signal is recovered with the first channel estimate, and interference due to the first signal is estimated and removed. A second channel estimate is derived with a second channel estimation filter having a second filter response that is different from the first filter response.

Abstract: A method and apparatus are provided for transmitting a multicarrier spread-spectrum signal formed by a temporal succession of multicarrier symbols, using OQAM modulation and a plurality of inter-orthogonal spreading codes. The method includes spreading at least one complex-value data symbol, representative of a source data signal to be transmitted, over a set of sub-carriers of at least one multicarrier symbol, each of the sub-carriers modulating a complex value.

Abstract: Interference, such as inter-symbol interference, from a symbol of interest in a RAKE receiver is reduced. The RAKE receiver comprises a plurality of RAKE fingers, a processor, and a combiner. The plurality of RAKE fingers despread symbols received over multiple paths of a multi-path channel. The processor determines cross-correlations between symbol waveforms from different symbols and multiple paths. The combiner combines the despread symbols using the cross-correlations to reduce interference from the symbol of interest.

Abstract: In an ad hoc peer-to-peer communication network between wireless devices, a low priory first transmitter device adjusts it transmit power based on a received transmission request response from a higher priority second receiver device. The first transmitter device broadcasts a first transmission request to a corresponding first receiver device and may receive a first transmission request response from a different second receiver device. The second transmission request response is sent by the second receiver device in response to a second transmission request from a second transmitter device. The first transmitter device calculates an interference cost to the second receiver device as a function of the received power of the first transmission request response. A transmission power is obtained as a function of the calculated interference cost and the transmission power of the first transmission request, the transmission power to be used for traffic transmissions corresponding to the first transmission request.

Abstract: The technology comprises method(s) and apparatus for operating a telecommunications system. In its basic form the method comprises providing plural channelization codes for potential use by an uplink receiver; using unused channelization codes of the plural codes to generate an estimate of an impairment covariance matrix; and using the estimate of the impairment covariance matrix to form a processing parameter. For example, the processing parameter can be one or more weight values which, in turn, are can be used for generating a combined output signal.

Abstract: A method of operating a base station node (21) comprises obtaining an indication of degradation of a radio link connection between the base station node and the user equipment unit (UE) which is carried by the a high speed packet channel (HSDPA). In accordance with the distance indication, the transmission priority for the radio link connection is modified. Preferably the indication of degradation is a distance indication of distance of a user equipment unit (23) involved in the radio link connection from the base station node (21). The transmission priority can be modified for one or both of downlink and uplink transmissions for the user equipment unit (UE). Preferably the transmission priority is modified for the radio link connection, e.g., for the user equipment unit (UE), as a function of the indication.

Abstract: A system and method for determining the performance of a channel emulator includes an input signal, at least one transmitter configured to receive the input signal, the at least one transmitter coupled to at least one receiver through the channel emulator, the at least one transmitter configured to transmit the input signal through the channel emulator, the at least one receiver configured to receive a faded receive signal. The system also comprises a signal processor configured to receive a processor signal and the faded receive signal, the signal processor configured to correlate the processor signal and the faded receive signal to develop a correlated signal that represents a channel impulse of the channel emulator. The channel impulse of the channel emulator is used to extract at least one channel coefficient that reflects the performance of the channel emulator.

Abstract: In a communication system, a method and an accompanying apparatus determine a number of available fingers (110A-N) in a receiver (100). A controller (121) adjusts a threshold based on the determined number of the available fingers (110). The adjusted threshold may be one of, or any combination of, a pilot signal search threshold, a lock/unlock threshold, and a combine/un-combine threshold. The number of available fingers (110) may change after the threshold is adjusted.

Abstract: Aspects of a method and system for channel estimation in a MIMO communication system with multiple RF chains for WCDMA/HSDPA may comprise receiving a plurality of communication signals from a plurality of transmit antennas. A plurality of vectors of baseband combined channel estimates may be generated based on phase rotation of the received plurality of communication signals. A matrix of processed baseband combined channel estimates may be generated based on the generated plurality of vectors of baseband combined channel estimates. A plurality of amplitude and phase correction signals may be generated based on the generated plurality of vectors of baseband combined channel estimates. An amplitude and a phase of at least a portion of the received plurality of communication signals may be adjusted based on the generated plurality of amplitude and phase correction signals, respectively.

Abstract: Apparatus and methods are disclosed for generating and managing a set of sectors, the signals received from which are utilized to generate an interference estimate for use by an interference cancellation circuit. The set of sectors generally includes a subset of the combined set of sectors in the Active Set and the Candidate Set for an access terminal. A finger of a receiver at an access terminal can be assigned to each sector in the set of sectors for interference cancellation to improve receiver operations. Other aspects, embodiments, and features are also claimed and described.

Abstract: A satellite receiver for receiving at least a target satellite signal includes a channel selection filter and a controller. The channel selection filter is provided with a plurality of channel selection settings conforming to characteristics of a plurality of satellite signals corresponding to different satellite systems, wherein each of the channel selection settings is to receive at least one of the satellite signals. The controller controls the channel selection filter to enable a target channel selection setting selected from the channel selection settings to thereby receive at least the target satellite signal.

Abstract: A wireless communications device having a complex vector quantization codebook for use in a downlink multi-user MIMO (multiple-input-multiple-output) mobile broadcast system with feedback enables the interference between data simultaneously sent by the base station to a plurality of mobile terminals to be reliably minimized. The codebook contains many subsets of code vectors that are substantially mutually (i.e., pairwise) orthogonal, or almost orthogonal, to each other. With use of such a codebook, a base station can transmit simultaneously to subsets of mobile terminals associated with these subsets of code vectors with minimal interference therebetween.

Abstract: Apparatus and methods for power control for mitigation or control of interference in a wireless communications environment. Power control techniques can consider the effectiveness of interference cancellation before making power control determinations. For example, where interference with a base station from an interfering wireless terminal is being canceled such that the effects of that interference are not adversely affecting operations of the base station, the offending terminal can be left unchanged, or its transmit power can be increased. On the other hand, where the interference cancellation operation is not able to cancel the effects of the interfering signal sufficiently, the operation can lower the uplink transmit power of the offending signal so as to not cause interference to the other base station.

Abstract: In an embodiment, an oversampled data converter includes a lowpass filter having a filter stage comprising a dynamic limiter, where the dynamic limiter having a limit set by an signal level at an input to the oversampled data converter. The oversampled data converter also includes a quantizing block comprising an input coupled to an output of the lowpass filter and an output coupled to an input of the lowpass filter.

Abstract: In a receive node of a wireless network, an iterative multi-user multi-stage interference cancellation receiver is used. After each stage of interference cancellation, interference characteristics change. An adaptive finger placement strategy is used in which after each stage of interference cancellation, finger delays and combining weights of the receiver are adapted to reflect the changed interference characteristics.

Abstract: A method and system for interference cancellation (IC). One aspect relates to traffic interference cancellation. Another aspect relates to joint IC for pilot, overhead and data. Another aspect relates to improved channel estimation. Another aspect relates to adaptation of transmit subchannel gains.

Abstract: A DAA (Detection And Avoidance) apparatus for use in a UWB receiver includes a frequency offset unit for adding a preset frequency offset to a UWB signal including a victim signal and an FFT unit for performing a fast-Fourier-transformation on the UWB signal with the frequency offset added thereto. The DAA apparatus further includes a DAA unit for detecting a victim signal from the fast-Fourier-transformed UWB signal and, when reception power of the victim signal is higher than a predetermined reference power level, changing a communication channel for the UWB signal to avoid interference.

Abstract: Systems, devices, processors, and methods are described which may be used for the reception of a wireless broadband signal at a user terminal from a gateway via a satellite. A wireless signal may include a series of physical layer frames, each frame including a physical layer header and payload. The received signal is digitized and processed using various novel physical layer headers and related techniques to synchronize the physical layer frames and recover data from physical layer headers for purposes of demodulation and decoding.

Abstract: A communication receiver implements receive space diversity to combine or select signals received from a same source on at least two spatially separated antennas in which the signals may vary in their fading characteristics at a given time. The receiver includes a RF processing module for down-converting and multiplexing the signals and a baseband processing module for converting the signals into digital signals, generating code sequences, producing despreaded and demultiplexed in-phase signals, and retrieving data initially contained within the received signals.

Abstract: A frequency tracking method applied to a positioning system is provided. The method includes receiving a baseband signal, the baseband signal includes a line of sight (LOS) signal and a multipath signal; generating a cost function according to equal step frequencies, the baseband signal and a signal average energy; and generating an estimated LOS frequency according to the cost function.

Abstract: The present invention relates to a method for decoding a composite radio signal at a receiver in an OFDM based radio communication system, said composite radio signal being a superposition of at least two signals sent by at least one transmitter, each signal having signal properties, in particular modulation scheme, coding scheme, said at least two signals being transmitted using the same radio resource on a set of frequency subchannels of said OFDM system. According to the present invention, the method comprises the steps of: gathering at said receiver information on said signal properties of the respective signals comprised in said composite radio signal; selecting, depending on said signal properties of said respective signals, the signal to be decoded first out of said composite radio signal; decoding said signal to be decoded first according to its signal properties, and subtracting the contribution of said signal to be decoded first from said composite radio signal.

Abstract: Block-encoded transmissions of a multi-antenna terminal unit are effectively detected in the presence of co-channel interfering transmissions when the base station has a plurality of antennas, and interference cancellation is combined with maximum likelihood decoding. More specifically, the signals received at the base station antennas are combined in a linear combination that relates to the channel coefficients between the various transmitting terminal units and the base antennas. By selecting proper coefficients for the linear combination and choosing probable transmitted signals that minimize a minimum mean squared error function, the signals of the various terminal units are canceled when detecting the signal of a particular unit. In another embodiment of the invention, the basic approach is used to obtain an initial estimate of the signals transmitted by one terminal unit, and the contribution of those signals is removed from the received signals prior to detecting the signals of other terminal units.

Abstract: A GNSS enabled communication device receives GNSS signals from GNSS satellites. The resulting GNSS baseband signals may be concurrently correlated with GNSS acquisition codes. Inter-delay products for the received GNSS signals may be generated utilizing the correlation IQ samples. The inter-delay products are utilized to calculate either an open loop or a close-loop estimate for inter-delay phase coherence of the received GNSS signals. A test statistic, generated from the inter-delay products, may be compared with a preset or dynamically determined threshold value in order to detect or declare signal degradation effects in the received GNSS signals. The early and late delays for the inter-delay phase coherence may be generalized to two or more delays. In this regard, the correlation IQ samples may be utilized to generate a correlation matrix. Variations derived from the correlation matrix may be utilized to declare or detect signal degradation effects in the received GNSS signals.

Abstract: A receiver in a CDMA system comprises a front end processor that generates a combined signal per source. A symbol estimator processes the combined signal to produce symbol estimates. An S-Matrix Generation module refines these symbol estimates based on the sub channel symbol estimates. An interference canceller is configured for cancelling interference from at least one of the plurality of received signals for producing at least one interference-cancelled signal.

Abstract: A intrusion detection system includes a first sensor device having a first transmission circuit unit that transmits a modulation wave of a first transmission spectrum diffusion signal to a first transmission leakage transfer passage and a second sensor device having a second transmission circuit unit that transmits a modulation wave of a second transmission spectrum diffusion signal to a second transmission leakage transfer passage. The signal interval of the first transmission spectrum diffusion signal is the same as the signal interval of the second transmission spectrum diffusion signal. The first transmission spectrum diffusion signal and the second transmission spectrum diffusion signal are shifted in frequency so that the first transmission spectrum diffusion signal does not overlap with the second transmission spectrum diffusion signal.

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: Methods and systems for processing signals in a receiver are disclosed herein and may comprise receiving spatially multiplexed signals via M receive antennas. A plurality of multiple data streams may be separated in the received spatially multiplexed signals to detect MIMO data streams. Each of the MIMO data streams may correspond to a spatially multiplexed input signal. Complex phase and/or amplitude may be estimated for each detected MIMO data streams utilizing (M-1) phase shifters. Complex waveforms, comprising in-phase (I) and quadrature (Q) components for the MIMO data streams within the received spatially multiplexed signals may be processed and the processed complex waveforms may be filtered to generate baseband bandwidth limited signals. Phase and/or amplitude for one or more received spatially multiplexed signals may be adjusted utilizing the estimated complex phase and amplitude. Phase and/or amplitude may be adjusted continuously and/or at discrete intervals.

Abstract: Apparatus and methods for power control for mitigation or control of interference in a wireless communications environment. Control techniques can consider the effect of interference on an access point and the access point can identify interfering wireless terminals and cause a message to be sent to a controlling access point of the interfering wireless terminal to cause the uplink power of the interfering wireless terminal to be adjusted.

Abstract: A system and method for mitigating multipath interference of signals in environments to determine the line of sight signal propagation.

Abstract: A navigation system includes a correlation engine configured to despread a received signal. The correlation engine includes a correlator configured to evaluate the received signal against a replica signal to produce a correlation result, and a packet encoder configured to produce a packet comprising a destination address, a source address, and the correlation result. An input/output interface is configured to provide the packet to another component in the navigation system.

Abstract: A system and method provides adaptive digital front end control of an incoming radio frequency (RF) signal to identify RF characteristics in that signal, such as interference or desired data signals and adaptively control digital filter elements to selectively tune only portions of the RF signal to produce a filtered output signal, on a per cycle basis, prior to communicating the RF signal to an underlying wireless communication device, such as a base station in cellular network, cellular phone, wireless router base station, cognitive radio, or other wireless communication device. Each digital filter element may be tuned in frequency and bandwidth of operation and collectively the elements form an adaptive filter stage with elements configurable into both bandpass and bandstop filters for cascaded operation.

Abstract: Implementations and techniques for collaborative data sharing for CDMA interference subtraction are generally disclosed.

Abstract: A method and system for reconstructing a user's received signal based on knowledge of the user's transmitted signal to yield efficient interference cancellation when there is spatial and/or temporal correlation in the received signal. The invention may be applied to the cancellation of pilot, decoded data and overhead signals. The method may involve a linear combination of the received samples across time, e.g., at a per-chip or sub-chip resolution, and across antennas, and build upon previous work in that the tap weights need not be the sole functions of the de-spreader outputs in the RAKE receiver.

Abstract: Apparatus and method for providing correlation in a CDMA receiver. A Generic Correlation Coprocessor comprises one or more correlation blocks. Each correlation block comprises a correlation input buffer coupled to one or more correlators. The correlators are coupled to an interpolator input buffer and to a correlator output buffer. One or more interpolators are coupled to the interpolation input buffer and to the correlation output buffer. The correlators correlate the received signal with PN codes to produce a correlated signal. The correlated signal is stored in the correlator output buffer and/or the interpolation input buffer, and provided from the interpolation input buffer to the one or more interpolators. The one or more interpolators interpolate the correlated signal to produce an interpolated signal. The interpolated signal is stored in the correlator output buffer. Signals are provided from the correlator output buffer to other receiver processing systems.

Abstract: A wireless receiver receives a signal obtained by multiplexing a plurality of signals that include a synchronization signal that is spread using a non-orthogonal code not orthogonal to a code for spreading other signals other than the synchronization signal. Then, in a case when the signals other than the synchronization signal are the target signals for decoding, the wireless receiver performs despreading with respect to the received signal using the synchronization signal and estimates the signal amplitude of the non-orthogonal code. Subsequently, the wireless receiver eliminates the spread synchronization signal from the received signal using the estimated signal amplitude of the non-orthogonal code and using the synchronization signal. Eventually, the wireless receiver performs despreading and demodulation with respect to the signal having the spread synchronization signal eliminated therefrom and decodes the target signals for decoding.

Abstract: An apparatus and a method for selecting a receiver for demodulating a reception signal at a reception end having a plurality of receivers are provided. The method includes determining, a mean and a standard deviation of Signal-to-Noise Ratios (SNRs) of the receivers are determined, estimating a Doppler frequency, determining a statistical value of a modulation order of subframes received in advance, determining SNR estimation values of the receivers based on the determined mean and standard deviation of the receivers, the estimated Doppler frequency, and the determined statistical value of the modulation order of the received subframes, selecting one receiver having a largest SNR estimation value among the determined SNRs of the receivers, and demodulating a reception signal using the selected receiver.

Abstract: A method, using a positioning module and a wireless telecommunication network comprises first and second base stations and first and second mobile terminals, said first terminal comprising a rake receiver, the method comprising: storing received signal data (MT_data) generated by the first mobile terminal rake receiver from signals transmitted over the air in a multipath environment and received by first mobile terminal; storing positioning data (MT_pos) obtained from the positioning module, said positioning data (MT_pos) comprising a plurality of positions of first mobile terminal with time associated with such position information; storing base station data obtained from first base station, said base station data comprising first base station identification code (BS_id) and first base station position information (BS_pos); determining field test data from said received signal data (MT_data), positioning data (MT_data) and base station data (BS_id, BS_pos), such determined field test data comprising: an

Abstract: A method and a system for storing a constant path loss exponent corresponding to free space; transmitting a signal; receiving the signal via a rake receiver of a user device; identifying a maximum received signal strength based on a signal strength associated with the signal relative to fingers of the rake receiver; storing a current maximum received signal strength value; determining whether the current maximum received signal strength value is a first maximum received signal strength value; calculating a current indoor position of the user device based on the constant path loss exponent and the current maximum received signal strength value when a determination is that the current maximum received signal strength value is the first maximum received signal strength value; and outputting the current indoor position.

Abstract: An apparatus includes a plurality of antennas, where each antenna is configured to receive wireless signals transmitted using adaptive beam forming. The apparatus also includes a plurality of wireless radios, where each wireless radio is configured to output signals representing the wireless signals received by one of the antennas. The apparatus further includes a plurality of first diversity combiner units, where each first diversity combiner unit is configured to perform spread spectrum diversity combining using the signals output by one of the wireless radios. In addition, the apparatus includes a second diversity combiner unit configured to perform antenna diversity combining using signals output by the first diversity combiner units, where the second diversity combiner unit is configured to output recovered wireless signals.

Abstract: A communication receiver includes first and second antenna elements for receiving first and second signals respectively representative of first and second symbols encoded with a first or second channel coefficient and first and second delay lines for delaying the first and second signals respectively. A master rake module up-samples a pilot channel sequence at chip rate to mix it with the second delayed signals to deliver correlated delayed signals and to determine first and second channel coefficient estimates from the first delayed signals and the correlated delayed signals. A slave rake module determines first and second auxiliary composite symbols from the first and second delayed signals, a scrambling code sequence and a spreading code sequence. Lastly the first and second auxiliary composite symbols combine with the first and second channel coefficient estimates to determine first and second output signals.

Abstract: Example embodiments of the systems and methods of dynamic spur mitigation for wireless receivers disclosed herein comprise one or more of a detection module for detecting the presence of a spur and a determination of its frequency, a complex notch filter chain, and a frequency locked loop which ensures that the input spur is notch filtered even if it drifts after detection. When a spur is detected, the frequency of the tone is determined. The spur is then filtered, for example using a phase rotator and a DC separator. The phase rotation is removed in a subsequent stage. The non-DC component from the DC separator is used to track the spur to compensate for any shifting or drifting in the spur.

Abstract: A method for effectively allocating a transmission power and a method for transmitting SCH are disclosed. In this case, the transmission power of the SCH, which is important for initial cell search of the user equipment, is increased but is not allocated to a predetermined frequency region within one OFDM symbol to obtain the increased transmission power, thereby minimizing an influence on transmission of other channels within one OFDM symbol.