Abstract: Methods and apparatus for efficiently feeding back preceding information in a multiple input multiple output (MIMO) system. A codebook including a plurality of codebook entries is constructed. A plurality of subsets of codebook entries are defined for the codebook. Each subset includes a plurality of codebook entries. A subset of codebook entries is selected for precoding data in dependence upon a channel condition, and a codebook entry is selected from the subset. Then, a subset index corresponding to the selected subset, and a codebook entry index corresponding to the selected codebook entry within the selected subset, is transmitted as feedback information.

Abstract: The method includes providing a stream of data to be transmitted, and processing the data by means of channel coding with a time-varying code rate, thereby generating a stream of channel coded data. The method further includes forming succeeding transmission time intervals and distributing the channel coded data on the transmission time intervals, and adjusting a transmission power of the signal to be transmitted by timely positioning a transmission power slope between two succeeding transmission time intervals so that the transmission power slope is contained completely within one transmission time interval of the two transmission time intervals, wherein the one transmission time interval comprises a lower nominal code rate or a lower nominal transmission power than the other one of the two transmission time intervals.

Abstract: Systems and methods for establishing transmission format parameters between communication devices are provided. In some aspects, a method includes identifying, by a first base station, a first communication session with a first user equipment. A master set of transmission format parameters is shared between the first base station and the first user equipment. The method also includes assigning a first subset of the master set of transmission format parameters to the first communication session. The first subset is specifically assigned to the first communication session and specifies which of the master set of transmission format parameters is allocated for use in the first communication session. The method also includes transmitting an indicator of the first subset to the first user equipment.

Abstract: The present invention relates to a method for transmitting a signal from a transmitter to a receiver through N number of transmitting antennas (where N?2), comprising: selecting a first and a second matrix from a first and a second codebook related to a first and a second precoding matrix indicator (PMI), respectively, and determining a precoding matrix on the basis of the first and second matrix; performing precoding by using the determined precoding matrix for L number of layers (where 1?L?N) to which a signal to be transmitted to the receiver is mapped; and transmitting the precoded signal to the receiver through the N number of transmitting antennas. Here, the first codebook includes one or more diagonal matrices having an N×N size, non-zero elements in the diagonal matrix has a predetermined phase value, and the second codebook includes one or more matrices having an N×L size.

Abstract: A sounding reference signal transmission method which is efficient in an uplink wireless telecommunications system using a multiple antenna technique and sounding reference signal hopping. A terminal using the multiple antenna technique is equipped with a plurality of antennas, and a base station receives the sounding reference signal transmitted from these antennas and estimates the uplink channel state of each antenna. Moreover, the sounding reference signal performs frequency hopping so that the base station determines the channel condition for the entire bandwidth to which data is transmitted in the uplink system. The sounding reference signal is transmitted through an antenna pattern in which the sounding reference signal can be transmitted through the entire data transmission bandwidth of the uplink system for each antenna of the terminal without additional overhead in this environment.

Abstract: A circuit for down-converting an RF signal to a baseband signal includes a trans-admittance amplifier adapted to receive the RF signal and generate in response a pair of differential current signals. The circuit further includes a trans-impedance amplifier having at least four mixers and at least four linear amplifiers. The four mixers frequency down-convert the pair of differential current signals to generate four pairs of differential baseband current signals, wherein each pair of the differential baseband current signals has a different phase and is associated with each of the linear amplifiers. Additionally, the circuit includes a summing block that generates an in-phase signal using a first weighted sum of the four different baseband current signals and a quadrature signal using a second weighted sum of the four different baseband current signals. The circuit further includes an analog-to-digital converter for converting the in-phase and quadrature signals to respective digital representations.

Abstract: A channel quality determining circuit includes a receiving circuit and a determining circuit. The receiving circuit is used for receiving a header of at least one packet transmitted in a signal transmitting channel. The determining circuit is coupled to the receiving circuit, and used for determining if a channel quality of the signal transmitting channel satisfies a predetermined quality standard according to the header of at least one packet.

Abstract: A hybrid MIMO RDN 3G/4G receiving system which include M antennas for N MIMO branches, wherein M>N is provided herein. Each branch has a beamformer so that each of the beamformers includes at least one combiner configured to combine signals coming from the antennas coupled to a respective beamformer into a combined signal. The system further includes a control module configured to tune at least one beamformer based on metrics derived by the baseband module. More specifically, the tuning of the beamformers is carried out, at least partially, using 3G/4G metrics that are generated but not usually reported in 3G/4G air protocols, wherein these metrics are extracted by the control module.

Abstract: A receiver for a wireless communication device provides a dual path receiver receiving first and second protocol-agnostic, uncorrelated receive signals simultaneously. The dual path receiver generating first and second offset IF signals from the simultaneously received first and second protocol-agnostic, uncorrelated receive signals. The receiver utilizes at least one converter for converting the first and second offset IF signals into at least one serial synchronous interface (SSI) signal representing the spectrum at IF. At least one processor receives the at least one SSI signal and applies parallel processing paths to demodulate the at least one SSI signal into separate baseband signals. The processor provides interference detection of, and level control for, the first and second offset IF signals.

Abstract: A method and an apparatus are provided for improving a communication rate, which are used in a terminal working in a multiple-input multiple-output (MIMO) state. The method includes: obtaining strength of a first signal received in a first path connected to a first antenna and strength of a second signal received in a second path connected to a second antenna; and adjusting the first path or/and the second path according to a difference between the strength of the first signal and the strength of the second signal, so as to reduce an unbalance degree between the first path and the second path, thereby improving the communication rate. By adopting the present invention, improvement of a rate of an antenna may be achieved by adjusting a balance between the first and second paths.

Abstract: Multi-function receivers are disclosed in which high dynamic range active microwave filters using nanoscale devices are disposed within a switched channelizer stage. In an embodiment the receiver includes an input low noise amplifier, a switched channelizer comprised of active filters utilizing nanoscale devices, an output amplifier, a mixer, and an analog to digital converter. Additionally, the use of highly selective active filters in the channelizer allows for the optional elimination of the mixing stage, improving cost and overall volume.

Abstract: Some demonstrative embodiments include devices, systems and/or methods of combining received wireless communication signals. For example, a device may include a radio-frequency (RF) combiner to combine first and second wireless communication RF signals of a wireless communication frame received via first and second respective antennas, into a combined signal; and a base-band phase estimator to estimate a phase difference between the first and the second antennas, and to provide to the RF combiner a feedback corresponding to the phase difference, wherein the radio-frequency combiner is to combine the first and the second RF signals according to the feedback.

Abstract: Systems and methods for suppressing interference from a data signal received at a receiving device, where the receiving device has two or more receive antennas, are provided. Characteristics of a channel are estimated, the channel being a channel through which the data signal was transmitted by a transmitting device to the receiving device. A spatial correlation of interference and noise received at the two or more receive antennas of the receiving device is determined based on the estimated characteristics of the channel. The spatial correlation indicates how the interference and noise received at a particular one of the receive antennas is related to the interference and noise received at another one of the receive antennas. The spatial correlation of the interference and noise is used to suppress interference and noise from the data signal received at the receiving device.

Abstract: A computing system includes: an inter-device interface configured to determine receiver description for representing a receiver signal corresponding to serving signal contemporaneous with an interference signal from an interference source at an interference-aware receiver; a communication unit, coupled to the inter-device interface, configured to: generate a pre-coding candidate set based on the receiver description for adjusting the serving signal or a subsequent instance thereof, determine a sum-rate condition for representing the serving signal along with the interference signal, and generate a pre-coding adjustment maximizing the sum-rate condition from the pre-coding candidate set for communicating the serving signal or a subsequent instance thereof.

Abstract: A method is provided. A multi-amplitude signal is received and downconverted so as to generate I and Q signals using a local oscillator signal. The I and Q signals are equalized, and the equalized I and Q signals are digitized. First and second gains are adjusted with the second and first digital signals, respectively, and applied to the equalized I and Q signals, respectively. The difference between the first and second amplified signals is determined, and an error signal is generated from the difference between the first and second amplified signals. The local oscillator signal is then adjusted with the error signal.

Abstract: Techniques are described for wireless communications. In one example, multiple signals including at least a wireless local area network (WLAN) signal and a cellular signal may be received over a bandwidth of an unlicensed radio frequency spectrum band. Digital samples of the signals may be stored in a buffer. At least a portion of the WLAN signal may be reconstructed from the stored digital samples and removed from the stored digital samples before the contents of the buffer are converted to the frequency domain for demodulation and decoding of the cellular signal by a cellular receiver. In another example, multiple signals may be received over a bandwidth of an unlicensed radio frequency spectrum band, and it may be determined whether to apply codeword-level interference cancelation (CWIC) or symbol-level interference cancelation (SLIC) to remove an interference signal in the multiple signals.

Abstract: In a MIMO system using a cross-polarized antenna structure, even if no ideal XPD can be obtained, the interference between different polarized waves can be reduced to allow an effective precoding to be executed. When a MIMO communication is performed between a transmitter and a receiver each using a cross-polarized antenna structure, a channel estimating and precoding selection section of the receiver performs a channel estimation of MIMO channels from the transmitter to the receiver, decides a precoding matrix of a projection matrix for mutually orthogonalizing or substantially orthogonalizing the channel response matrixes for respective different polarized waves, and feeds the determined precoding matrix back to the transmitter. In the transmitter, a precoding processing section applies the precoding matrix to the spatial stream corresponding to one of the polarized waves to perform a precoding, thereby allowing the transmitter to transmit the polarized waves with the orthogonality therebetween maintained.

Abstract: In one or more embodiments, system(s), method(s), integrated circuit(s), physical layer(s), apparatus(es), System-on-Chip (SoC), various other hardware, computer-readable and/or executable instructions, and/or technique(s) are described that enable lower power consumption and/or maximize channel utilization for devices communicating wirelessly in the 60 GHz range. These embodiments enable handheld devices to use less power when communicating with wall-powered or other higher-powered devices while still enabling the wall-powered devices to communicate effectively with each other by maximizing channel utilization.

Abstract: A process selects a Precoding Matrix Index (PMI) in a Multiple In Multiple Out (MIMO) receiver used in a wireless communications system including a base station communicating with User Equipments (UE) through a downlink and uplink channel. The base station applies a precoding on the transmit symbol vector based on a matrix selected from a set of predefined matrices and identified by a PMI index computed by the UE and forwarded to the base station via the uplink. The process includes estimating the MIMO channel matrix H of a given set of resources blocks comprising received symbol vectors, estimating the variance ?2 of the additive noise (AWGN), and computing for each particular matrix comprised within the set of predefined matrices a cost function representative of the orthogonality of the matrix MIMO channel matrix H.

Abstract: A system for processing data streams or signals includes a wave-front multiplexer configured to process first and second input signals into first and second output signals each carrying information associated with the first and second input signals, a first processing unit configured to process a third input signal carrying information associated with the first output signal into a third output signal, a second processing unit configured to process a fourth input signal carrying information associated with the second output signal into a fourth output signal, and a wave-front demultiplexer configured to process fifth and sixth input signals into fifth and sixth output signals each carrying information associated with the fifth and sixth input signals. The fifth input signal carries information associated with the third output signal, and the sixth input signal carries information associated with the fourth output signal.

Abstract: A radio device receives a band-limited signal and estimates signal components beyond the band edges to extend the signal and eliminate the band-limited effects. The extended signal is transformed to the time domain to produce an estimate of the true time domain channel.

Abstract: An exemplary embodiment of the present invention provides an incremental lattice reduction method comprising: receiving an input signal at a plurality of input terminals; evaluating a reliability assessment condition using a primary symbol vector estimate of at least a portion of the input signal; terminating the incremental lattice reduction method if the reliability assessment condition is satisfied; and if the reliability assessment condition is not satisfied, performing at least one iteration of a lattice reduction detection sub-method to obtain a secondary symbol vector estimate.

Abstract: Apparatus, the apparatus having at least one processor and at least one memory having computer-readable code stored thereon which when executed controls the at least one processor to perform a method comprising: obtaining in-phase and quadrature samples of a received radio signal at least first and second discrete instances in time; processing the samples to provide information relating to the amplitude and/or phase of the received radio signal at the first and second instances in time; using the amplitude and/or phase information of the received radio signal at the first and second instances in time to determine whether interference is present on the received radio signal; forwarding the complex signal parameters for processing if interference is determined not to be present; and discarding the complex signal parameters without forwarding them for processing if interference is determined to be present.

Abstract: The present invention employs hierarchical modulation to simultaneously transmit information on different modulation layers using a carrier RF signal. Initially, first data to be transmitted is assigned to a first modulation layer and second data is assigned to a second modulation layer. In one embodiment of the present invention, the first and second data are assigned based on reliability criteria. The first and second modulation layers are hierarchical modulation layers of the carrier RF signal. Once assigned, the first data is transmitted using the first modulation layer of the carrier RF signal and the second data is transmitted using the second modulation layer of the carrier RF signal. In one embodiment of the present invention, information may be transmitted to one end user using one modulation layer, and information may be transmitted to a different end user using a different modulation layer.

Abstract: A method and system is provided for detecting the presence of a DVB (digital video broadcasting) transmission. The method includes receiving an RF (radio frequency) signal in a selected channel (1101); creating signal samples from the received RF signal (1102); creating averaged samples from the signal samples, each averaged sample being an average of a predetermined number of signal samples that are separated by a minimum pilot pattern repetition period from one to the next signal sample (1103); correlating the averaged samples with a reference sequence (1104); and comparing a correlation result with a threshold correlation value (1105).

Abstract: Systems and methods are provided for channel estimation using linear phase estimation. These systems and methods enable improved channel estimation by estimating a linear channel phase between received pilot subcarrier signals. The estimated linear phase can then be removed from the received pilot subcarrier signals. After the estimated linear phase is removed from the received pilot subcarrier signals, a channel response can be estimated. A final estimated channel response can be generated by multiplying the results of the linear channel estimation by the estimated linear phase.

Abstract: A method of demodulating a plurality of multiplexed modulation signals is provided, including: i) inputting the plurality of multiplexed modulation signals, each of which being outputted from a plurality of outputs of a communication partner, wherein each modulation signal in the multiplexed modulation signals includes a pilot symbol sequence consisting of a plurality of pilot symbols used for demodulation, ii) estimating respective channels of the multiplexed modulation signals based on one or more of the pilot symbol sequences; and iii) demodulating each modulation signal in the plurality of multiplexed modulation signals based on the channel estimation. Each of the pilot symbol sequences is inserted at a same temporal point in each modulation signal among the multiplexed modulation signals. The pilot symbol sequences are orthogonal to each other with zero cross correlation among the modulation signals in the multiplexed modulation signals, and each pilot symbol has a non-zero amplitude.

Abstract: A signal receiver may comprise a first sampling circuitry that is operable to sample in a first level at a particular main sampling rate; a second sampling circuitry that is operable to sample in a second level, an output of the first sampling circuitry, at a second sampling rate that is reduced compared to the main sampling rate; a third sampling circuitry that is operable to sample in a third level, one or more outputs of the second sampling circuitry, at a third sampling rate that is reduced compared to the second sampling rate; and an analog-to-digital conversion (ADC) circuitry for applying analog-to-digital conversion to one or more outputs of the third sampling circuitry.

Abstract: A method, receiver and program for processing radio signals to identity an n-ray channel condition. The method comprises: receiving signal samples and estimating a plurality of channel taps from the samples; estimating for each of the channel taps a signal power and a disturbance power; filtering the signal power to provide a filtered signal power quantity; filtering the disturbance power to provide a filtered disturbance power quantity; using the filtered power quantities to determine n strongest channel taps; generating first and second comparison parameters using the strongest channel taps and at least one other channel tap; providing a comparison result based on the first and second comparison parameters and a threshold value, and; identifying an n-ray channel condition from the comparison result.

Abstract: An automatic gain control (AGC) method and system for a radio receiver are proposed in which the ACG comprises two AGC loops; a first loop controlling signal gain in the analog portion of the radio receiver, a second loop controlling gain in the digital domain after digitization of the received signal. The analog AGC loop has a slower response time than the digital AGC loop. When applied to a multi-branch diversity receiver, each branch has its own digital AGC loop, but the analog gain can be common to all branches, based on measurement of the analog signal in each branch.

Abstract: A channel estimation method in a multipath channel, and which includes receiving a signal from a channel having multipath; obtaining information related to the number of paths and synchronization information related to each path from the received signal; estimating a channel using the obtained information related to the number of paths and synchronization information related to each path; calculating a metric using at least one impulse response value of a Square Root Raised Cosine (SRRC) filter and the obtained information; calculating an inverse metric of the calculated metric; and removing an inter-path interference from the estimated channel by multiplying the inverse metric with the estimated channel.

Abstract: Systems and methods for reading RFID tags using joint beamforming and preamble detection in accordance with embodiments of the invention are disclosed. One embodiment includes an antenna array comprising a plurality of antenna elements, a joint beamformer and preamble detector configured to receive inputs from each of the antenna elements, and a decoder configured to receive a resampled signal from the joint beamformer and preamble detector and to decode data using the resampled signal. In addition, the joint beamformer and preamble detector is configured to correlate the inputs from the antenna elements against a correlation sequence at a plurality of starting sample positions and predetermined rates, use the correlations to select a starting sample position and rate for decoding the received signal, use the correlations to determine beamforming coefficients for combining the inputs, and resample the combined inputs based upon the selected starting sample position and rate.

Abstract: A method and device for decoding in a differential orthogonal space-time block coded system are disclosed. The disclosed method includes: (a) receiving signals from a transmitter during a particular time slot segment, where the signals are encoded by differential orthogonal space-time block coding; (b) transforming to reception signals for two sub-systems by using a sum operation and a difference operation of the signals received in step (a), where the transformed reception signals for the two sub-systems maintain an orthogonality of an orthogonal space-time block coded system; and (c) performing decoding using the reception signals for the two sub-systems transformed in step (b). The method provides the advantage of lowering the level of operational complexity for decoding in a communication system that employs differential orthogonal space-time block coding.

Abstract: In a MIMO system using a cross-polarized antenna structure, even if no ideal XPD can be obtained, the interference between different polarized waves can be reduced to allow an effective precoding to be executed. When a MIMO communication is performed between a transmitter and a receiver each using a cross-polarized antenna structure, a channel estimating and precoding selection section of the receiver performs a channel estimation of MIMO channels from the transmitter to the receiver, decides a precoding matrix of a projection matrix for mutually orthogonalizing or substantially orthogonalizing the channel response matrixes for respective different polarized waves, and feeds the determined precoding matrix back to the transmitter. In the transmitter, a precoding processing section applies the precoding matrix to the spatial stream corresponding to one of the polarized waves to perform a precoding, thereby allowing the transmitter to transmit the polarized waves with the orthogonality therebetween maintained.

Abstract: The present invention relates to a method and system for channel estimation. First, pilot signals are extracted from a received multi-path signal, in which each pilot signal includes a first pilot and a second pilot. Then, an initially estimated channel frequency-domain response is obtained based on the extracted first pilot. Afterward, a frequency-domain response estimate of each pilot frequency in the second pilot is calculated according to the obtained initially estimated channel frequency-domain response, an actual value of each pilot frequency in the second pilot is obtained based on the extracted second pilot, and a deviation between the frequency-domain response estimate and the actual value of each pilot frequency is calculated. When it is detected that aliasing components exist in the initially estimated channel frequency-domain response, a center of each aliasing component is determined according to the deviation, so as to determine an estimated position of each aliasing component.

Abstract: The description herein relates to pilot designs for an Orthogonal Frequency Division Multiplexing (OFDM) based communication system. In at least one embodiment, the communication system is one operating according to the IEEE 802.16m, or WiMax, standard. In general, an OFDM transmitter operates to insert pilot symbols into a resource of a transmit frame according to a predetermined staggered pilot symbol pattern defining pilot symbol locations within the resource of the transmit frame. The predetermined pilot symbol pattern is defined such that pilot symbols are located at or near time boundaries of the resource, at or near frequency boundaries of the resource, or both. By doing so, when generating a channel estimate for the communication channel between the OFDM transmitter and an OFDM receiver based on the pilot symbols, extrapolations needed to estimate the channel near the boundaries of the resource are optimized, thereby improving overall channel estimation accuracy.

Abstract: Providing for reduced complexity or improved accuracy in de-mapping received wireless data streams for multi-channel wireless communication is described herein. By way of example, a low-complexity likelihood algorithm can be employed to de-map data bits from the wireless data streams. In one particular example, the likelihood algorithm can approximate a received bit with a subset of received wireless symbols correlated the bit, reducing algorithm complexity. In other examples, a limited set of received wireless symbols can be employed for the subset, further reducing algorithm complexity. According to at least one other example, logarithmic terms of the algorithm can be approximated with non-logarithmic functions, such as a look-up table, series expansion, polynomial approximation, or the like. These approximations can enhance symbol de-mapping accuracy while maintaining or improving processing overhead for a wireless receiver.

Abstract: Methods and apparatus are described for processing data in a wireless communication network. Iterative estimation techniques are used to enable tracking of time-varying communication channels. A signal is transmitted over a channel in the network, the signal comprising a sequence of symbols carried on a plurality of sub-carriers. Boot-up estimator (304) estimates, in a time domain, parameters of a model of the channel based on the received signal. A domain converter (206) transforms at least one of the estimated parameters from the time domain to provide at least one transformed parameter in a second domain. An equalizer (210) and decoder (212) determine estimates of symbols from the received signal using the at least one transformed parameter, and tracking estimator (314) updates the estimated model parameters during reception of the signal using at least one estimated symbol.

Abstract: A method includes, in a mobile communication terminal, receiving from at least first and second base stations, which cooperate in a coordinated transmission scheme, signals that are transmitted over respective first and second communication channels. Respective channel measures are calculated for the communication channels based on the received signals. First and second feedback data, which are indicative of the respective channel measures of the first and second communication channels, are formulated such that the first feedback data has a first data size and the second feedback data has a second data size, different from the first data size. The first and second feedback data are transmitted from the mobile communication terminal to at least one of the base stations.

Abstract: In a wireless modem which comprises a first receiver and a second receiver it is detected whether or not user data transmission is taking place. If user data transmission is detected, a second channel quality value is continuously estimated using the second receiver. If no user data transmission is detected, the second receiver is shut off, a first channel quality value is continuously estimated using the first receiver, and the second channel quality value of the second receiver is continuously estimated using the first channel quality value estimated by the first receiver.

Abstract: Various embodiments associated with multiple signal editions is described. A plurality of sensors can be deployed in an environment. These sensors can be used to capture a signal of interest (SOI). However, when the signal is weak or difficult to sense, what an individual sensor captures may be of little value. Therefore, multiple sensors can be used together to capture the signal (e.g., different editions of the SOI). Further, it is possible that the demodulation scheme of the signal is not known, such as when the signal is from an unknown network (e.g., a network of an enemy). A mathematical operation can be performed upon signal editions such that a result does not include noise. This result can be used in determining the demodulation scheme of the signal.

Abstract: The present invention provides a communication circuit, a communication network, and a connecting apparatus that can realize communication with very high reliability using a simple wiring system, that includes a communication line 2 comprising three or more signal lines 2a,2b,2c, a signal distributing section 4, that is connected to one end of the communication line 2, for distributing and transmitting a signal input into an input terminal 3i to respective signal lines 2a,2b,2c, and a majority selection receiving circuit 5, that is connected to the other end of the communication line 2, for comparing a plurality of reception signals received via the signal lines 2a,2b,2c and selecting reception signals which are most matched with one another as true so as to output them to an output terminal 30.

Abstract: Methods and apparatuses are described for a direct sampling receiver having high dynamic range and low noise figure with a continuous-time (CT) multiplying digital-to-analog converter (MDAC) architecture. In a multipath architecture, the input signal is sampled in the quantizer path, but not the CT signal path. In the CT signal path, only a filtered residue signal is sampled. Coarse bits generated in the quantizer path and fine bits generated in the input signal path are digitally combined to reconstruct the analog input signal in the digital domain. Filtering, aperture error control and digital equalization remove sources of errors, resulting in high performance. Advantages include toleration of multiple blocker signals, simultaneous reception of multiple weak channels and/or strong and weak channels, operation with simplified gain control and reduced pre-amplification as well as operation without excessive power consumption, external filters and tunable local oscillator (LO).

Abstract: The invention relates to a method of receiving a signal corresponding to a multicarrier signal transmitted via at least one transmission channel, the method comprising an estimation step (11) of estimating said channel and delivering overall information about said channel in the frequency domain, referred to as a “frequency response” and comprising frequency samples. According to the invention, such a method also comprises: a sharing step (12) of sharing said frequency samples in at least two frequency sample vectors; a transform step (13) of transforming said frequency sample vectors from the frequency domain to a transform domain and delivering, for at least one frequency sample vector, a partial response of said channel in said transform domain; and a feedback step (14) of transmitting a return signal back to said transmitter, the return signal conveying samples extracted from said partial responses and representative of said channel in said transform domain.

Abstract: A radio may define a channel plan to include one or more channels, and each channel may include a plurality of overlapping filters. Each filter may overlap at least one other filter, such as by an expected bandwidth of an incoming signal. The overlapping filters may extend over a frequency range based in part on an expected frequency error of the incoming signal. Due in part to the overlapping nature of the filters, the incoming signal will be within at least one of the filters. Since only one of the filters must receive the incoming signal, the filters may be narrower than might otherwise be the case, particularly in an application that includes frequency error. Accordingly, the filters may be narrower than their respective channels, and therefore receive less noise and interference. This improves signal-to-noise and improves the quality of the link and range.

Abstract: A method for transmitting a sounding reference signal in a MIMO wireless communication system and an apparatus therefor are disclosed. The method for transmitting sounding reference signals (SRSs) in a MIMO wireless communication system comprises receiving sounding reference signal parameters from a base station; receiving information of the number of sounding reference signals which will be transmitted at a transmission time instant from the base station; if a plurality of sounding reference signals are provided, generating the sounding reference signals corresponding to each of the plurality of antennas by using the sounding reference signal parameters; and transmitting the generated sounding reference signals to the base station through their corresponding antennas at a specific transmission instant.

Abstract: An outdoor radio communication system comprises a first radio unit, a second radio unit, and a single cable coupling the first radio unit to the second radio unit. Each radio unit includes a downconverter, a radio processor that is communicatively coupled to the downconverter, and a XPIC module. The cable further includes a first twisted-pair of wires for communicatively coupling the first downconverter to the second XPIC module and a second twisted-pair of wires for communicatively coupling the second downconverter to the first XPIC module. The first XPIC module generates a first reference signal using a signal from the second downconverter to cancel cross-polarization interference in an output signal of the first radio processor. Similarly, the second XPIC module generates a second reference signal using a signal from the first downconverter to cancel cross-polarization interference in an output signal of the second radio processor.

Abstract: A method, implementable on a multiple-input, multiple-output symbol receiver, includes selecting a hypothesis for a second symbol value U2 from among the set of fixed constellation points, calculating a hypothesis for a first symbol value U1 from the resultant selected U2 value, and generating a first half of counter-hypotheses from interim results of calculating the hypotheses values.

Abstract: Example embodiments comprise a diversity receiver, and corresponding method, for measuring a differential phase between a first local oscillator of a first antenna and a second local oscillator of a second antenna in the presence of a primary interference signal and at least one secondary interference signal. The method may comprise receiving a primary communication signal, a primary reference signal and additional reference signals, and processing these signals such that a summation signal does not substantially comprise the at least one secondary interference signal. The estimation of differential phase is achieved by a phase shift calculation between processed signal components, using that a summation of all signal components equals, or is approximately equal to, a predetermined signal.

Abstract: A multi user receiver configured to receive a signal including multiple symbol streams assigned to various users is described. The multiple symbol streams include at least one first symbol stream assigned to a user of the multi user receiver and at least one second symbol stream assigned to another user, wherein a modulation alphabet applied for the at least one second symbol stream is unknown at the multi user receiver. The multi user receiver includes a symbol stream election unit configured to elect a symbol stream of the multiple symbol streams, an equalizer configured to provide an equalized symbol of the elected symbol stream, and a detector configured to generate a detected symbol from the equalized symbol on the basis of a constellation, wherein, if the second symbol stream is elected, the constellation is a mixed constellation including constellation points of at least two of multiple predefined modulation alphabets.