Abstract: One implementation of the disclosed technology involves detecting a transition in a signal received via one of a first indexed input and a second indexed input. The transition defines a first symbol having a symbol value. This implementation further involves outputting the first symbol in response to detection of a transition. The symbol value of the first symbol is designated by the index of the indexed input upon which the transition is detected.

Abstract: Disclosed are a wireless communication method of improving frequency efficiency based on a channel function in a wireless communication system and an apparatus thereof. The wireless communication system using a digital modulation scheme, includes: a transmitting apparatus which modulates a data signal to generate a modulation symbol, generates a channel symbol function corresponding to the modulation symbol, combines the modulation symbol with the channel symbol function to generate a transmission symbol to transmit the generated transmission symbol through a transmission antenna; and a receiving apparatus which receives the transmission symbol through a reception antenna, estimates a channel symbol function included in the transmission symbol, and extracts the data signal based on the modulation symbol included in the transmission symbol.

Abstract: A system and method for aggregation of a plurality of wireless communication signals in a common radio frequency transmitter. A multiple subchannel multiplexed (MSM) signal within a frequency band, and having a communication protocol with pilot signals estimating a channel state and efficient signal demodulation with a mobile receiver is combined with another signal. An automated digital processor at the transmitter modifies the MSM to meet at least one fitness criterion of the combined signal, selected from among alternatives that will maintain good reception of all transmitted signals within system protocols, without requiring transmitting additional side information specifying the modification. The range of alternates include modifications that disrupt the pilot signals.

Abstract: There is provided a signal processing device including a first correction processing section that performs first correction on a predetermined signal, an adaptive processing section that performs predetermined adaptive processing on the signal that has been subjected to the first correction, and a second correction processing section that performs second correction, which is reverse correction of the first correction, on the signal that has been subjected to the adaptive processing, in accordance with the amount of delay in the adaptive processing.

Abstract: An ASIC for monitoring wideband GHz spectrum to sense respective frequency components present in the spectrum. The ASIC implements Fast Fourier Transform (FFT) techniques to facilitate identification of one or more frequency components of a sparse signal after the signal is sub-sampled at a rate below the Nyquist criterion. The ASIC computes a first Fast Fourier Transform (FFT) of a first sub-sampled set of samples of a time-varying signal representing the monitored spectrum and sampled at a first sampling rate, and further computes a second FFT of a second sub-sampled set of samples of the time-varying signal sampled at a second sampling rate different from the first sampling rate. In one example, each of the first FFT and the second FFT is a low-radix FFT to facilitate a low-power and low-cost ASIC implementation of wideband spectrum sensing.

Abstract: Disclosed are methods and a device for Multi-resolution PMI Feedback. In one implementation, a user equipment finds a rank 1 or rank 2 Precoding Matrix Indicator based on the signal channel matrix and interference covariance matrix, defines an error vector, obtains an orthonormal basis for the projection matrix, finds the (M?1)-dimensional vector from a codebook (e.g., oversampled Discrete Fourier Transform) with the minimum Euclidean distance, and sends a feedback representing to the base station regarding the vector that it found in the codebook.

Abstract: This disclosure provides systems, methods, and apparatus for receiving paging messages in fast fading scenarios. In one aspect, a method of demodulating a paging message during an assigned time slot by a wireless communications apparatus operating in an idle mode is provided. The method includes determining, in anticipation of the assigned time slot, an expected time position corresponding to a path of a pilot signal having a greater signal strength relative to other pilot signals. The method further includes assigning a first demodulation element to demodulate the pilot signal with reference to the expected time position and assigning a second demodulation element to demodulate the pilot signal with reference to a time offset from the expected time position. Other aspects, embodiments, and features are also claimed and described.

Abstract: An adaptive filter bank can be implemented on a PLC device to dynamically adapt to variations in notching requirements and the performance of the PLC medium. The PLC device can apply filter coefficients to one or more filter elements of the adaptive filter bank to generate one or more notched subcarriers in the PLC band. A performance measurement of one or more subcarriers in the PLC band can be determined and evaluated against corresponding performance measurement thresholds. For a given notched subcarrier, if the performance measurement of the corresponding subcarriers is not in accordance with the performance measurement threshold, updated filter coefficients for the filter element configured to generate the notched subcarrier can be determined based, at least in part, on the performance measurement of the one or more subcarriers. The filter coefficients of the filter element can then be updated using the updated filter coefficients.

Abstract: Systems and methods for carrier phase recovery are provided. One method includes providing a reference signal, detecting an input signal and determining a Signal to Noise Ratio (SNR) of the input signal. The method also includes employing a Minimum Mean Square Error (MMSE) algorithm based on the SNR to determine a Carrier Phase Recovery Loop (CPRL) bandwidth.

Abstract: A demodulator processes a continuous-time signal to generate at a plurality of encoded bits. An inner decoder processes a first subset of bits within the plurality of encoded bits to correct selected ones of the first subset of bits to form a corrected first subset of bits and to generate partially corrected data from the plurality of encoded bits based on the corrected first subset of bits. An outer decoder processes the partially decoded data, to correct selected ones of a second subset of the plurality of encoded bits to form a corrected second subset of bits. A bit combiner generates data estimates by combining the corrected first subset of bits and the corrected second subset of bits.

Abstract: A method and system for combining a guard interval and a corresponding portion of a received symbol, whereby when receiving a signal that contains the symbol with a guard interval corresponding to the symbol, a portion of the guard interval that is free from inter-symbol interference may be extracted, and the extracted portion of the guard interval may be combined with the corresponding portion of the symbol. The extracting and combining may be done after a determining, based on a delay profile provided by the received signal, that a delay spread is smaller than a predetermined channel delay. The delay spread may be determined by filtering an instantaneous delay spread associated with the received signal. The filtering may be performed using a 1-tap infinite impulse response low-pass filter. The low-pass filter may include a time constant that is the inverse of a maximum Doppler frequency shift.

Abstract: A method and an apparatus for transmitting broadcast signals thereof are disclosed. The apparatus for transmitting broadcast signals comprises an encoder encoding service data, a time interleaver interleaving the encoded service data, a mapper mapping the interleaved service data into a plurality of OFDM (Orthogonal Frequency Division Multiplex) symbols to build at least one signal frame, a frequency interleaver frequency interleaving data in the at least one signal frame by using a different interleaving-seed which is used for every OFDM symbol pair comprised of two sequential OFDM symbols, wherein the frequency interleaving is performed by using two memories, a modulator modulating the frequency interleaved data by an OFDM scheme and a transmitter transmitting the broadcast signals having the modulated data, wherein an interleaving-seed is generated based on a cyclic shift value and an FFT size of the modulating.

Abstract: A method includes receiving a data unit that includes a signal (SIG) field and a data field. The SIG field provides information for interpreting the data field. The method also includes detecting a first symbol constellation rotation of at least a first orthogonal frequency division multiplexing (OFDM) symbol in the SIG field of the data unit, determining, based at least in part on the detected first symbol constellation rotation, a number of information bits per OFDM symbol in the SIG field of the data unit, processing the SIG field of the data unit according to the determined number of information bits per OFDM symbol in the SIG field, and processing the data field of the data unit according to the information for interpreting the data field as provided in the SIG field of the data unit.

Abstract: A phase detection method includes providing by a controller a second control signal having two or more neighboring pulses when the time during which a state of a second control signal is retained is a predetermined time or more, receiving by the controller phase detection results of a phase of a first control signal different from the second control signal in response to the second control signal, and determining by the controller a phase detection result based on a first pulse of the two neighboring pulses of the second control signal, of the phase detection results.

Abstract: Electronic devices are adapted to facilitate data encoding for simultaneously limiting both instantaneous current and signal transitions. According to one example, an electronic device may perform a first encoding scheme on a group of data bits to be transmitted on a data bus. The first encoding scheme may be performed based on a number of transitions within the group of data bits for each data channel. A second encoding scheme may also be performed on the group of data bits. The second encoding scheme may be performed based on a number of data bits within the group of data bits for each data channel exhibiting a predetermined state (e.g., a one or a zero). After both encoding scheme are performed on the group of data bits, the encoded data bits may be transmitted over respective data channels of the data bus. Other aspects, embodiments, and features are also included.

Abstract: A receiver applies a calibration method to compensate for skew between input channels. The receiver skew is estimated by observing the coefficients of an adaptive equalizer which adjusts the coefficients based on time-varying properties of the multi-channel input signal. The receiver skew is compensated by programming the phase of the sampling clocks for the different channels. Furthermore, during real-time operation of the receiver, channel diagnostics is performed to automatically estimate differential group delay and/or other channel characteristics based on the equalizer coefficients using a frequency averaging or polarization averaging approach. Framer information can furthermore be utilized to estimate differential group delay that is an integer multiple of the symbol rate. Additionally, a DSP reset may be performed when substantial signal degradation is detected based on the channel diagnostics information.

Abstract: One aspect provides an optical communication system. The system includes an optical-to-digital converter, a frequency estimator and a symbol synchronizer. The optical-to-digital converter is configured to receive an optical OFDM bit stream including an OFDM symbol bearing payload data and a symbol header preceding the OFDM payload data. The frequency estimator is configured to determine a carrier frequency offset of the payload data from the symbol header. The symbol synchronizer is configured to determine a starting location of the payload data within the bit stream by cross-correlating a synchronization pattern within the symbol header with a model synchronization pattern stored by the symbol synchronizer.

Abstract: A system for performing maximum ratio combining on a plurality of symbols corresponding to a transmitted symbol. A plurality of antennas is configured to receive, via respective communication channels, respective ones of the plurality of symbols. An automatic gain control is configured to modify each of the plurality of symbols using a respective gain. The respective gains are different for each of the plurality of symbols. A channel estimator is configured to generate, for each of the respective communication channels, a channel estimate in accordance with a respective one of the plurality of symbols as modified using the respective gain. A demodulator is configured to generate, in accordance with the channel estimates and the plurality of symbols as modified using the respective gains, a maximum ratio combining output and demodulate the maximum ratio combining output to generate a demodulated plurality of symbols.

Abstract: A receiving device including: a demodulation circuit configured to generate first likelihood data of reception symbols based on a transmission format of the reception symbols, the transmission format being selected from transmission formats and including a modulation scheme applied to the reception symbols, the modulation scheme being one of amplitude modulation schemes, a processor configured to estimate a scale ratio of an implementation scale to a theoretical scale, the implementation scale being a scale of the first likelihood data, the theoretical scale being a scale of second likelihood data of the reception symbols, the second likelihood data being defined by a theory and not depending on an implementation of the receiving device, and to generate the second likelihood data based on the first likelihood data and the scale ratio, and a decoding circuit configured to decode the second likelihood data based on the transmission format.

Abstract: A method and apparatus for detecting an envelope are provided. The method and apparatus may detect an envelope of a modulating signal based on a low calculation complexity and a simple circuit configuration, by detecting an envelope for a plurality of sampling signals with equal time intervals.

Abstract: A demapping scheme, having a low computational cost, suitable for any transmission in which only exhaustive demapping can guarantee good performance. The scheme, proposed in this document, can be used in any transmission based on no differential modulation. For example the proposed scheme can be directly applied to a transmission on flat fading AWGN channels or to a transmission on frequency selective channels after equalization or on each sub-carrier of an OFDM System. The proposed solution can be applied for the demapping of any communication system. The proposed scheme can be used for rotated and un-rotated constellation.

Abstract: A wideband phase detector configured to receive an intermediate frequency (IF) signal having a plurality of information signals at predetermined carrier frequencies and to generate a carrier indication signal used to control one or more attenuators to equalize the signal levels of the information signals thereby enabling a multichannel receiver to process the two information signals in a parallel fashion using a common analog front-end and analog to digital conversion circuit. The circuit may include an attenuation controller configured to provide control signals to the one or more attenuators to attenuate one or more corresponding information signals based on an average of the carrier indication signal.

Abstract: Systems and methodologies are described that facilitate frequency hopping in a single carrier FDMA wireless environment by dynamically altering user offsets with time to obtain interference diversity. A channel tree can be utilized with nodes that are assigned values. User devices can be assigned to such nodes, a path between an assigned node and a root node in the channel tree can be evaluated, and a table lookup can be performed to determine an identity of a subcarrier set to assign to the user device assigned to a given node, as well as a number of subcarriers to be assigned to the user device. Additionally, node values can be dynamically varied during a communication event to alter path values and thus alter subcarrier set assignments.

Abstract: A receiver is configured to receive a sample of an inter-symbol correlated (ISC) signal, the sample corresponding to a time instant when phase and/or amplitude of the ISC signal is a result of correlation among a plurality of symbols of a transmitted symbol sequence. The receiver may linearize the sample of the ISC signal. The receiver may calculate a residual signal value based on the linearized sample of the ISC signal. The receiver may generate an estimate of one or more of said plurality of symbols based on a slicing of the residual signal value. The linearization may comprise applying an estimate of an inverse of a non-linear model. The non-linear model may be a model of nonlinearity experienced by the ISC signal in a transmitter from which the ISC signal originated, in a channel through which the ISC signal passed en route to the receiver, and/or in a front-end of the receiver.

Abstract: A device and method for demodulation of multiple received signals is provided. The device can have a receiver configured to receive a composite signal having two or more constituent signals overlapped in frequency. The device can have one or more processors configured to determine a at least one modulation type and at least one symbol rate corresponding to the two or more constituent signals. The one or more processors can further resample the composite signal at a sampling rate that is a multiple of the at least one symbol rate to determine the characteristics of the two or more constituent signals. The one or more processors can separate and output the two or more constituent signals using the determined characteristics.

Abstract: A method, performed in a receiver device, for decoding transmissions of a set of coded information bits from a transmitter. The method includes deriving received symbols from first received data and second received data. The received symbols are converted to sets of soft coded bit estimates. The sets of soft coded bit estimates are combined to form a combined set of soft coded bit estimates. The combined set of soft coded bit estimates are decoded to form a set of soft information bit estimates. The set of soft information bit estimates are converted to form a set of binary bits. A determination is made whether the set of binary bits has been correctly or incorrectly decoded. Interference cancellation is performed on the received data, and the method is repeated until either the set of binary bits has been correctly decoded or a predefined maximum number of iterations is reached.

Abstract: The present disclosure relates to an iterative method for estimating covariance matrices of communication signals comprising a) computing a reference symbol covariance matrix estimate (k,l); b) inputting said reference symbol covariance matrix estimate (k,l) to a detector or a decoder in a first iteration, and thereafter inputting the covariance matrix estimate output from e) to the detector or the decoder in subsequent iterations to obtain an updated demodulated or decoded communication signal for each iteration; c) inputting the demodulated or decoded communication signal to a symbol generator; d) computing an updated data covariance matrix estimate (k,l) for each iteration based on data symbols of said regenerated communication signal; e) combining said reference symbol covariance matrix estimate (k,l) and said updated data covariance matrix estimate (k,l); and f) forwarding said covariance matrix estimate output to the detector or decoder in b) to obtain the updated demodulated or decoded communicati

Abstract: A method may comprise receiving and sampling a signal. The signal may encode a data packet. A slice may be generated and stored comprising a pair of values for each of a selected number of samples of the signal representing a correlation of the signal to reference functions in the receiver. The presence of the data packet may then be detected and the detected packet decoded from the stored slices. The generating and storing slices may be carried out as the received signal is sampled. The sampled values of the signal may be discarded as the slices are generated and stored. The slice representation of the signal can be manipulated to generate filters with flexible bandwidth and center frequency.

Abstract: System and method embodiments are provided for high efficiency wireless communications. In an embodiment, a method in a network component for transmitting a frame of two different fast Fourier transform (FFT) sizes includes generating a frame, wherein the frame comprises orthogonal frequency-division multiplexing (OFDM) symbols in two different FFT sizes, wherein the frame comprises a first portion and a second portion, wherein the first portion comprises a first FFT size and the second portion comprises a second FFT size; and transmitting the frame during a single transmission opportunity.

Abstract: A radio communication apparatus operable over a wide range of frequencies including a signal processing device is provided. The device performs an analog to digital conversion at a predetermined sample rate independent of a selected frequency band within the wide range of frequencies to generate a digital signal, and digitally processes the digital signal to output a data signal at baseband associated with the selected frequency band.

Abstract: Most wireless channels are sparse, so sparse channel-based methods can be used for channel estimation and feedback with much better estimation accuracy and much lower feedback overhead. However, certain wireless channels can be non-sparse, for which sparse channel-based methods may cause degraded estimation quality and increased feedback overhead. Means of detecting the channel sparseness are described that provide simple and effective channel sparseness indicators and safeguard against the mismatch between non-sparse channels and sparse channel-based methods. Various fallback options can be used under non-sparse channels such that estimation degradation and feedback overhead are both minimized. Fake multipath removal in continuous time-domain parameter extraction, a sparse channel-based method, is also described that further improves estimation quality and reduces feedback overhead.

Abstract: Repeatedly: pre-processing a received signal using feedback to obtain a pre-processed signal, the feedback being based on a previous signal, the previous signal being received prior to the received signal; evaluating at least one of a quality of a demodulated signal and a quality of a decoded signal, the demodulated signal being obtained from the pre-processed signal by demodulating, the decoded signal being obtained by decoding the demodulated signal; deciding if the respective at least one of the quality of the demodulated signal and the quality of the decoded signal is sufficient; selecting neither or one of the demodulated signal and the decoded signal as a selected signal based on the at least one of the quality of the demodulated signal and the quality of the decoded signal for which it is decided whether or not the quality is sufficient; and updating the feedback based on the selected signal.

Abstract: A wireless communication system includes a base station capable of communicating with a plurality of subscriber stations. The base station can transmit control information and data to a subscriber stations. The base station also can identify a set of RS patterns to be used to communicate with the subscriber station, assign a subset of antenna port numbers within the set of RS patterns to the subscriber stations. The base station can indicate the assigned states in a Downlink Control Information (DCI) format transmitted in a Physical Downlink Control Channel (PDCCH). The base station transmits the data using a subset of antenna ports corresponding to the subset of antenna port numbers. The base station also can map reference signals corresponding to the subset of antenna ports according to at least one RS pattern within the set of RS patterns.

Abstract: A digital down converter is disclosed. The digital down converter includes an input for receiving a sampled signal having a frequency band of interest, sampled at a first sampling rate, a commutator structure for distributing a set of real sampled signals for polyphase filtering, a complex band pass polyphase filter associated with the distributed signals, for generating in phase and quadrature filtered components, a baseband notch filter, and a frequency translator for generating in phase and quadrature components of the frequency band of interest at baseband.

Abstract: A channel frequency response estimator for estimating the channel frequency response of a wireless RF channel having a time or frequency varying channel frequency response is disclosed. The channel frequency response estimator includes a wireless receiver. An ambiguous channel frequency response estimator is also included and configured to establish multiple channel frequency response estimate candidates for the channel frequency response of the channel. An ambiguity resolver is configured to select a channel frequency response estimate from the multiple channel frequency response estimate candidates that maximizes a goodness of fit of the selected first channel frequency response estimate, and at least two further channel frequency response estimates to a channel model. The channel model models the time or frequency dependent variance of the channel frequency response.

Abstract: A communication apparatus according to the present invention comprises first communication means configured to transmit differential signals serving as first information over a first wire pair; second communication means configured to transmit differential signals serving as second information over a second wire pair; and third communication means configured to transmit third information by transmitting one of differential signals over the first wire pair and transmitting the other of the differential signals over the second wire pair. It is possible to provide a communication apparatus that spurious emission is suppressed.

Abstract: Systems and methods are disclosed herein to provide improved channel estimation in a wireless data communication system, including but not limited to Multiple Input Multiple Output (MIMO) and Orthogonal Frequency Division Multiplexing (OFDM) communication systems. In accordance with one or more embodiments and aspects thereof, a channel estimation system is disclosed that regenerates a representation of the original transmitted signal from the received digital bitstream and selectively applies it to refine and improve channel estimation and signal equalization calculations using the data symbols contained within received frames. Such a system may offer improved capabilities such as more accurate signal reception, reduced bit error ratio, and improved Multi-User MIMO (MU-MIMO) reception.

Abstract: Multi-level symbols generated by applying a Random Projection Code (RPC) to a source bit sequence are received at a receiver via a noisy channel. The received multi-level symbols are represented in a bipartite graph as constraint nodes connected via weighted edges to binary variable nodes that represent the source bit sequence. A decoder uses ZigZag deconvolution to generate constraint node messages as part of an iterative belief propagation to decode the source bit sequence from the received multi-level symbols.

Abstract: A reception apparatus obtains a first channel estimated value from a reference signal of each layer and a known reference signal that are received and multiplies the first channel estimated value by an orthogonal signal sequence in each layer. Subsequently, the reception apparatus synthesizes a signal in each layer and, from the orthogonal signal sequence and the synthesized signal, calculates an adaptive array antenna weight. Next, the reception apparatus carries out antenna synthesis of the data signal and the reference signal by using the above weight for each layer and obtains a second channel estimated value from the reference signal subjected to the synthesis. Then, the reception apparatus carries out MIMO demodulation from a result of the channel estimation for each layer described above.

Abstract: An element selection unit (200) and a method therein for vector element selection. The element selection unit comprises a selector control circuit (404) and a selector data path circuit (406), which data path circuit comprises a plurality of layers of multiplexers. The element selection unit further comprises a receiving circuit (401) configured to receive an instruction to perform a selection of elements from an input vector. The selector control circuit (404) is configured to generate a multiplexer control signal for each multiplexer based on a bit map and on a plurality of relative offset values. The data path circuit is configured to propagate the elements comprised in the input vector through the plurality of layers of multiplexers towards an output vector based on the generated multiplexer control signals. The data path circuit is further configured to write the propagated elements to enabled elements of the output vector.

Abstract: Certain aspects of the present disclosure relate to techniques for generating likely demodulation candidates using Vector Candidate Sampling (VCS). VCS is used to generate high likelihood candidates for Multiple Input Multiple Output (MIMO) demodulation that approaches optimal maximum a posteriori (MAP) performance with reasonable complexity. A receive data vector is recorded corresponding to a signal received at a MIMO receiver. A plurality of likely candidates are determined for MIMO demodulation via VCS, based at least on the receive data vector. Determining the likely candidates may include perturbing the receive data vector for each candidate based on a pre-determined perturb vector, and estimating a corresponding transmit data vector based at least on the perturbed receive data vector for the candidate and an estimator matrix, wherein the likely candidate comprises the estimated data vector.

Abstract: An apparatus for reconstructing digital video data stream reconstructs a transport stream from a first data stream and a second data stream. Both of the first data stream and the second data stream comprise a plurality of packets, a plurality of input stream time reference (ISCR) values, and a plurality of deleted null packet (DNP) values. The apparatus includes a packet interval detector, that estimates a packet interval according to the first data stream or the second data stream; an alignment unit, that generates an alignment signal according to the ISCR values and the packet interval; an oscillator, coupled to the packet interval detector, that generates an output pulse signal; and a reconstruction controller, that reconstructs the transport stream from the first data stream and the second data stream and outputs the transport stream according to the alignment signal and the output pulse signal.

Abstract: A precoding method, a precoding apparatus, a Frequency Domain Equalization (FDE) method, and an FDE apparatus are provided in the embodiments of the present invention. The precoding method includes: performing offset modulation for a transmitting signal vector; calculating a precoding matrix according to the offset-modulated transmitting signal vector and a receiver decision signal vector, where the precoding matrix is used for performing precoding for the transmitting signal vector; and performing precoding for the transmitting signal vector according to the precoding matrix. Linear precoding is performed by using the offset-modulated signal on the transmitter, and therefore, the interference caused by multiple antennas and multipath propagation is reduced, the system BER is reduced, and the complexity of implementation is low.

Abstract: The approach shown provides for an efficient implementation of time response, level response and frequency response alignment between two audio sources such as DAB and FM that may be time offset from each other by as much as 2 seconds, and produces an aurally undetectable transition between the sources. Computational load is significantly reduced over the approaches known in the prior art.

Abstract: In one embodiment, a receiver may receive a signal from a transmitter. The receiver may include a first sampler that may sample the signal when the value of the signal is zero. The receiver may further include a second sampler that may sample the signal halfway between a time when the first sampler samples the signal and the next time when the first sampler samples the signal to produce a set of sampled values. The receiver may be further operable to determine that a sampled value in the set of sampled values is a logic 1 if the sampled value is greater than the value of a reference voltage and that the sampled value is a logic 0 if the sampled value is less than the value of the reference voltage.

Abstract: A receiver front end circuit includes a low-noise amplifier including: a first receiver path having: a first low-noise transconductor to amplify a received signal and output the amplified received signal; and a first mixer to down-convert the amplified received signal. A second receiver path includes: an auxiliary receiver having: a second transconductor to output an amplified received signal; a baseband amplifier having an input port and an output port; a first resistance coupling the input port to the output port of the baseband amplifier and to convert the amplified received signal from current to voltage and set a voltage gain of the second receiver path; and a second resistance coupled from the output port of the baseband amplifier to the first mixer output. In some examples, frequency-upconversion feedback path includes a third mixer to frequency up-convert the amplified received signal at an output of the second receiver path.

Abstract: The present invention relates to a software radio system and a decoding apparatus and method thereof. According to an embodiment of the present invention, there is provided a forward error correction decoding apparatus for a software radio system, including: a receiving module for receiving decoding tasks from a plurality of uplink channels; and a decoder matrix for executing the decoding tasks, wherein the decoder matrix is shared by the plurality of uplink channels. The decoding apparatus and method as well as the software radio system according to the embodiments of the present invention can be well adapted to the high computing capabilities, sufficient flexibility and scalability as required by base station systems for next-generation wireless communication systems.

Abstract: The present invention discloses microwave communications devices. The microwave communications device includes: a first converting module, a second converting module, configured to perform mutual conversion between a baseband signal or an intermediate frequency signal and a microwave signal, where microwave signals received or output by the first converting module and the second converting module respectively have a same polarization direction or perpendicular polarization directions; and an orthomode transducer with three waveguide ports, configured to perform separation and synthesis of orthogonally polarized microwave signals, The microwave communications devices in embodiments of the present invention can, by providing dual channels and integrating an orthomode transducer inside the microwave communications device, increase a transmission capacity while improving equipment application flexibility, reducing installation complexity, and lowering costs.

Abstract: An RFVGA variably controls a gain according to an RFVGA gain control signal and amplifies and outputs a reception signal. A low-pass filter filters a signal output from a frequency converter. An OFDM demodulator generates a digital signal based on an output signal from the low-pass filter. A power detection evaluation circuit controls the RFVGA gain control signal based on a voltage value (DET0) of the RFVGA gain control signal or a voltage value (DET1) of the output signal from the RFVGA, and a voltage value (DET3) of an output signal from the low-pass filter and a voltage value (DET2) of an intermediate node of the low-pass filter.

Abstract: An enhanced VSB receiver includes a tuner which tunes an RF signal and converts it into an IF signal, an IF mixer which converts the IF signal into a baseband signal, and a demodulator which demodulates the baseband signal into a VSB signal. The enhanced VSB receiver further includes a map recovery unit which recovers VSB map information of the VSB signal, an enhanced equalizer for compensating channel distortion of the VSB signal and outputting an equalized symbol, and an enhanced Viterbi decoder for estimating whether polarity inversion occurred during a symbol period of the equalized symbol and Viterbi-decoding the equalized symbol based on the polarity estimation.