Abstract: Aspects of the disclosure relate to a method of operating a scheduled entity for wireless communication. In some aspects, the scheduled entity detects a fluctuation in a beam strength of at least one transmit beam from a scheduling entity. The scheduled entity transmits a first message to the scheduling entity, the first message indicating at least the fluctuation in the beam strength of the at least one transmit beam from the scheduling entity.

Abstract: In some examples, a binary bit stream of input bits is encoded into a three-amplitude bipolar symbol stream of symbols, the encoding using a coding rule that specifies setting a value of a respective symbol of the symbol stream based on a respective input bit of the binary bit stream and a prior input bit of the binary bit stream that is prior to the respective input bit, the coding rule further specifying that adjacent non-zero pulses keep the same polarity. A radio frequency (RF) carrier signal is modulated using the symbol stream to produce a modulated RF signal.

Abstract: An encoding method for encoding input information bits using an encoder implemented with concatenation of a CRC-? coder and a polar coder is provided. The method includes performing Cyclic Redundancy Check (CRC) coding on as many information bits as a determined number of CRC coding bits among input information bits and performing polar coding on the CRC-coded information bits and other information bits than the CRC-coded information bits.

Abstract: An n-order noise shaper has an order n?3, wherein a first set of polynomial coefficients are optimized with respect to a useful band and wherein a second set of polynomial coefficients are optimized with respect to an optimization aim depending on an overall out of band noise and/or on a maximum out of band noise.

Abstract: Systems and methods for detecting collisions in radio frequency tags in accordance with embodiments of the invention are disclosed. In one embodiment, a receiver system includes a receiver configured to receive and sample a phase modulated input signal, and a multiple symbol noncoherent soft output detector configured to receive the sampled input signal and to generate a soft metric indicative of the reliability of a detected symbol based upon observations over multiple symbols, a collision detector configured to calculate a decision metric from a set of soft metrics generated by the multiple symbol noncoherent soft output detector and detect a collision when the decision metric satisfies a predetermined criterion.

Abstract: A method and system for a sequence estimation in a receiver, such as for use when receiving a sample of a received inter-symbol correlated (ISC) signal corresponding to a transmitted vector of L symbols, with L being a integer greater than 1, and with symbol L being a most-recent symbol and symbol 1 being least recent symbol of the vector. A plurality of candidate vectors may be generated, wherein element L?m of each candidate vector holding one of a plurality of possible values of the symbol L?m, with m is an integer greater than or equal to 1, and elements L?m+1 through L of each candidate vectors holding determined filler values. A plurality of metrics may be generated based on the plurality of candidate vectors, and based on the generated plurality of metrics, a best one of the possible values of the symbol L?m may be selected.

Abstract: In one embodiment, a method for wireless communication includes receiving cell information for a cluster of cells to be coordinated. A first cluster scheduling order used for the cluster of cells is retrieved. The first cluster scheduling order represents a sequence in which the cluster of cells were scheduled in a previous schedule. A second cluster scheduling order is generated. The second cluster scheduling order determines a sequence in which the cluster of cells are scheduled in an upcoming schedule. The second cluster scheduling order is decided based on the first cluster scheduling order and/or the cell information. The second cluster scheduling order is transmitted to the cluster of cells.

Abstract: The present invention provides a digital broadcast receiver which reduces the time needed for channel scans by performing efficient channel scanning when broadcasts in a plurality of broadcast protocols are received. As a first phase channel scan, a first controller and a second controller divide a plurality of channels included in an overlapping frequency band of a first broadcast protocol and a second broadcast protocol, and execute parallel channel scans. After the first phase channel scan, the first controller scans channels in which electrical signals generated from electromagnetic waves received by a second tuner in the first phase channel scan could not be demodulated by a second demodulator, and the second controller scans channels in which electrical signals generated from electromagnetic waves received by a first tuner could not be demodulated by a first demodulator.

Abstract: A frequency translating analog-to-digital converter for receiving an analog band-pass signal is described. The analog-to-digital converter comprises an adder/input block for receiving the analog band-pass signal and an analog band-pass feedback signal, thereby forming an analog band-pass error signal. The analog-to-digital converter has at least one analog mixer for mixing and down converting the analog band-pass error signal and thus generating a down-converted analog error signal and at least one quantization path for generating at least one digital signal.

Abstract: A transmitter may comprise a symbol mapper circuit and operate in at least two modes. In a first mode, the number of symbols output by the mapper circuit per orthogonal frequency division multiplexing (OFDM) symbol transmitted by said transmitter may be greater than the number of data-carrying subcarriers used to transmit the OFDM symbol. In a second mode, the number of symbols output by said mapper circuit per orthogonal frequency division multiplexing (OFDM) symbol transmitted by said transmitter is less than or equal to the number of data-carrying subcarriers used to transmit said OFDM symbol. The symbols output by the symbol mapper circuit may be N-QAM symbols. While the circuitry operates in the first mode, the symbols output by the mapper may be converted to physical subcarrier values via filtering and decimation prior to being input to an IFFT circuit.

Abstract: A receiver may be operable to receive an inter-symbol correlated (ISC) signal, and generate a plurality of soft decisions as to information carried in the ISC signal. The soft decisions may be generated using a reduced-state sequence estimation (RSSE) process. The RSSE process may be such that the number of symbol survivors retained after each iteration of the RSSE process is less than the maximum likelihood state space. The plurality of soft decisions may comprise a plurality of log likelihood ratios (LLRs). Each of the plurality of LLRs may correspond to a respective one of a plurality of subwords of a forward error correction (FEC) codeword.

Abstract: A MIMO detection method for a receiver in a MIMO system using N-QAM for modulation, the MIMO detection method including generating a plurality of symbol vector sets and a plurality of search radiuses, selecting a candidate symbol vector set corresponding to a highest level of a multilevel structure of N-QAM constellation, generating a search space corresponding to a lower level of the multilevel structure of N-QAM constellation according to the selected candidate symbol vector set, confirming which level the search space corresponds to, and generating a detection signal according to the search space when the level of the search space is the lowest level of the multilevel structure of the N-QAM constellation.

Abstract: A method and an apparatus for allocating a resource in a broadband wireless communication system are provided. In the method, a Modulation and Coding Scheme (MCS) level set and a burst size set to generate a codebook is determined. The codebook is generated using the MCS level set and the burst size set. Resource allocation information is one of generated and read according to the codebook.

Abstract: A method for generating sequences that are nearest to a set of sequences with minimum average cross-correlation is described. Each element of a set of sequences is projected to a nearest constellation point. The set of sequences is converted into a time domain representation. An inverse discrete Fourier Transform (IDFT) is performed on the set of sequences. A cubic metric of each sequence of the set of sequences is evaluated. A sequence is removed from the set if the cubic metric exceeds a threshold. A minimum maximum cross-correlation is obtained for the set of sequences.

Abstract: A method and system for a sequence estimation in a receiver, such as for use when receiving a sample of a received inter-symbol correlated (ISC) signal corresponding to a transmitted vector of L symbols, with L being a integer greater than 1, and with symbol L being a most-recent symbol and symbol 1 being least recent symbol of the vector. A plurality of candidate vectors may be generated, wherein element L-m of each candidate vector holding one of a plurality of possible values of the symbol L-m, with m is an integer greater than or equal to 1, and elements L-m+1 through L of each candidate vectors holding determined filler values. A plurality of metrics may be generated based on the plurality of candidate vectors, and based on the generated plurality of metrics, a best one of the possible values of the symbol L-m may be selected.

Abstract: Disclosed is a digital broadcasting transmission/reception system having an improved reception performance and a signal-processing method thereof. A digital broadcasting transmitter comprises a TS stream generator for inputting robust and normal packets having stuff bytes in predetermined positions and generating dual TS stream by inserting the robust packets between the normal packets; a randomizer for randomizing the dual TS stream; a stuff byte exchanger for replacing the stuff bytes of a randomized data streams from the randomizer to a predetermined known data; and an encoder for encoding a data streams to which the known data is inserted. Accordingly, the present invention detects the known data from a signal received from a reception side and uses the detected known data for synchronization and equalization, so that the digital broadcasting reception performance can be improved at poor multipath channels.

Abstract: Disclosed is a digital broadcasting transmission/reception system having an improved reception performance and in a signal-processing method thereof. A digital broadcasting transmitter comprises a TS stream generator for inputting robust and normal packets having stuff bytes in predetermined positions and generating dual TS stream by inserting the robust packets between the normal packets; a randomizer for randomizing the dual TS stream; a stuff byte exchanger for replacing the stuff bytes of a randomized data streams from the randomizer to a predetermined known data; and an encoder for encoding a data streams to which the known data is inserted. Accordingly, the present invention detects the known data from a signal received from a reception side and uses the detected known data for synchronization and equalization, so that the digital broadcasting reception performance can be improved at poor multipath channels.

Abstract: Disclosed is a digital broadcasting transmission/reception system having an improved reception performance and in a signal-processing method thereof. A digital broadcasting transmitter comprises a TS stream generator for inputting robust and normal packets having stuff bytes in predetermined positions and generating dual TS stream by inserting the robust packets between the normal packets; a randomizer for randomizing the dual TS stream; a stuff byte exchanger for replacing the stuff bytes of a randomized data streams from the randomizer to a predetermined known data; and an encoder for encoding a data streams to which the known data is inserted. Accordingly, the present invention detects the known data from a signal received from a reception side and uses the detected known data for synchronization and equalization, so that the digital broadcasting reception performance can be improved at poor multipath channels.

Abstract: Techniques are provided for performing hierarchical coding in a multi-antenna communication system (e.g., a SIMO, MISO, or MIMO system). At a transmitter, a base stream and an enhancement stream are coded and modulated separately to obtain first and second data symbol streams, respectively. The first data symbol stream is processed in accordance with a first spatial processing scheme (e.g., a transmit diversity or a spatial multiplexing scheme) to obtain a first set of symbol substreams. The second data symbol stream is processed in accordance with a second spatial processing scheme (e.g., transmit diversity or spatial multiplexing) to obtain a second set of symbol substreams. The first set of symbol substreams is combined (e.g., using time division multiplexing or superposition) with the second set of symbol substreams to obtain multiple transmit symbol streams for transmission from multiple transmit antennas. A receiver performs complementary processing to recover the base stream and enhancement stream.

Abstract: A receiver may be operable to receive a QAM-based, inter-symbol correlated (ISC) signal at a signal-to-noise ratio of between 29 dB and 31 dB and process the QAM-based, ISC signal to output estimated symbols at a symbol error rate of between 2×10?1 and 1×10?3. The QAM-based, ISC signal may be a partial response signal generated by passing a first signal through a partial response pulse shaping filter. The partial response pulse shaping filter may provide greater capacity than a capacity achieved by passing the first signal through a root-raised-cosine-based pulse shaping filter. The receiver may comprises an input filter, and the processing of the QAM-based, ISC signal may comprises filtering the QAM-based, ISC signal via a filter configured to achieve a desired total partial response in combination with the partial response pulse shaping filter.

Abstract: Disclosed is a digital broadcasting transmission/reception system having an improved reception performance and in a signal-processing method thereof. A digital broadcasting transmitter comprises a TS stream generator for inputting robust and normal packets having stuff bytes in predetermined positions and generating dual TS stream by inserting the robust packets between the normal packets; a randomizer for randomizing the dual TS stream; a stuff byte exchanger for replacing the stuff bytes of a randomized data streams from the randomizer to a predetermined known data; and an encoder for encoding a data streams to which the known data is inserted. Accordingly, the present invention detects the known data from a signal received from a reception side and uses the detected known data for synchronization and equalization, so that the digital broadcasting reception performance can be improved at poor multipath channels.

Abstract: A reproduction signal evaluation method evaluates the quality of a reproduction signal reproduced from an information recording medium based on a binary signal generated from the reproduction signal using a PRML signal processing system. A pattern extraction step extracts, from the binary signal, a specific state transition pattern which has the possibility of causing a bit error; a step computes a differential metric based on the binary signal; an extraction step extracts the differential metric which is not greater than a predetermined signal processing threshold; a step determines a mean value of the differential metrics which are not greater than the signal processing threshold and extracted in the extraction step; a standard deviation computing step determines a standard deviation which corresponds to an error rate predicted from the mean value; and an evaluation step evaluates a quality of the reproduction signal using the standard deviation.

Abstract: According to one exemplary embodiment, a method for producing an up-converted and amplified transmission signal comprises performing a logarithmic transformation of an input transmission signal to form a logarithmically transformed transmission signal, adding the logarithmically transformed transmission signal to a logarithmic local oscillator signal to form a sum signal, and performing an antilogarithmic transformation of the sum signal to produce the up-converted and amplified transmission signal. In one embodiment, a log-antilog circuit for producing an up-converted and an amplified transmission signal comprises a transmission log block configured to receive an input transmission signal and to provide a logarithmically transformed transmission signal as a transmission log block output, and an antilog block coupled to the transmission log block. The antilog block is configured to receive a sum signal of the transmission log block output and a logarithmic local oscillator signal.

Abstract: Disclosed is a digital broadcasting transmission/reception system having an improved reception performance and in a signal-processing method thereof. A digital broadcasting transmitter comprises a TS stream generator for inputting robust and normal packets having stuff bytes in predetermined positions and generating dual TS stream by inserting the robust packets between the normal packets; a randomizer for randomizing the dual TS stream; a stuff byte exchanger for replacing the stuff bytes of a randomized data streams from the randomizer to a predetermined known data; and an encoder for encoding a data streams to which the known data is inserted. Accordingly, the present invention detects the known data from a signal received from a reception side and uses the detected known data for synchronization and equalization, so that the digital broadcasting reception performance can be improved at poor multipath channels.

Abstract: Various aspects of a method for minimum mean square error soft interference cancellation (MMSE-SIC) based sub-optimal maximum likelihood (ML) detection for a multiple input multiple output (MIMO) wireless system may comprise selecting at least one constellation point in a constellation map based on at least one of a plurality of received symbols. A number of the at least one constellation point may be less than or equal to a number of previously selected constellation points in a previous constellation map. At least one of the plurality of received symbols may be decoded based on the selected at least one constellation point.

Abstract: The present invention relates to impulse noise estimation and removal in orthogonal frequency division multiplexing (OFDM) transmissions, and particularly to transmissions in power line communications and digital subscriber line (DSL) transmissions. The method includes the steps of: modulating data to be transmitted; performing an inverse fast Fourier transform; inserting a cyclic prefix into the data; transmitting the data as a set of OFDM symbols via a channel; receiving the set of OFDM symbols; removing the cyclic prefix; performing a fast Fourier transform; estimating impulse noise; canceling the impulse noise based upon the estimated impulse noise to produce a set of impulse noise-free data; estimating the channel; and demodulating and detecting the data transmitted based upon the estimated channel and the set of impulse noise-free data.

Abstract: An apparatus and method to feedforward non-quantized precoding weights in an OFDM communication system includes a first step (300) of sending feedback information from a subscriber station (SS) to a base station (BS). A next step (302) includes deriving non-quantized weight information from the feedback information. A next step (304) includes transmitting symbols carrying the non-quantized weight information and non-precoded pilot symbols by the BS. A next step (305) includes receiving the information and symbols by the SS. A next step (306) includes estimating the non-quantized weights from the symbols carrying the non-quantized weight information and the non-precoded pilot symbols by the SS. A next step (308) includes decoding data from the BS by the SS using the estimated non-quantized weight information.

Abstract: A reproduction signal evaluation method evaluates the quality of a reproduction signal reproduced from an information recording medium based on a binary signal generated from the reproduction signal using a PRML signal processing system. The method includes a pattern extraction step of extracting, from the binary signal, a specific state transition pattern which has the possibility of causing a bit error; a step of computing a differential metric based on the binary signal; an extraction step of extracting the differential metric which is not greater than a predetermined signal processing threshold; a step of determining a mean value of the differential metrics which are not greater than the signal processing threshold and extracted in the extraction step; a standard deviation computing step of determining a standard deviation which corresponds to an error rate predicted from the mean value; and an evaluation step of evaluating a quality of the reproduction signal using the standard deviation.

Abstract: Procedures performed prior to convolutional interleaving of 8VSB digital television signals restrict the alphabet of symbols in novel methods of generating trellis-coded digital television signals that include more robust symbol coding using a restricted alphabet of symbols selected from a full 8VSB symbol alphabet consisting of ?7, ?5, ?3, ?1, +1, +3, +5 and +7 normalized modulation levels superposed on a background modulation level. Certain of these novel procedures generate pseudo-2VSB or P-2VSB robust symbol coding with a restricted alphabet of symbols consisting of ?7, ?5, +5 and +7 normalized modulation levels superposed on a background modulation level. Others of these novel procedures generate prescribed-coset-pattern-modulation or PCPM robust symbol coding intermixing two restricted alphabets of symbols according to a prescribed pattern. One of the two restricted alphabets of symbols used in PCPM consists of ?3, ?1, +5 and +7 normalized modulation levels superposed on a background modulation level.

Abstract: Multi-carrier transmission is performed without inserting a repetitive signal into guard interval periods. A transmitter provides guard interval periods by using a null signal to save transmission power and prevent the deterioration of the SN ratio. Delayed waves at the head of each received symbol cause high-frequency waves to occur and carriers to interfere with one another. Accordingly, a receiver adds a component following each received symbol to a delayed-wave component at the head of the received symbol. As a result, the delayed-wave component at the head of the received symbol and the added component become continuous in wave form and subcarriers do not interfere with each other.

Abstract: System and methods for reducing the complexity or area of a non-linear Viterbi detector. In some embodiments, a Viterbi detector calculates branch metrics for a subset of the branches in a trellis diagram. This subset may be selected based on comparing an equalized signal with a signal level table of all the possible branches. These branch metrics may be calculated using high performance branch metric calculation techniques. The remaining branch metrics may be calculated based on the computed branch metrics using a technique that consumes fewer resources. The Viterbi detectors in the present invention may also be used in an iterative decoding scheme, where multiple detectors are cascaded. In these embodiments, a Viterbi detector may select a subset of the branches based on detection results from other Viterbi detectors.

Abstract: Disclosed herein is a decoding apparatus for decoding channel input bits from a partial-response channel output in accordance with a trellis obtained by combining a coding constraint and state transitions of a partial response for a case in which the length of a memory required for describing the coding constraint is greater than the length of a channel memory of the partial response. The apparatus may include a first calculation unit configured to carry out a first calculation on first branch information, which may be defined as information on first branches included in three or more branches merging in a state determined in advance, and first path information defined as information on first paths for the first branches; and a second calculation unit configured to carry out a second calculation on a first calculation value obtained as a result of the first calculation.

Abstract: A method of feeding back channel information in an OFDM or OFDMA radio communications system is disclosed, in which a transmitting side instructs a region for measuring a downlink channel status and in which a receiving side feeds back the channel information to the transmitting side. The present invention includes the steps of transmitting instruction information instructing at least one region of at least two regions within a data frame as a signal measurement region to a receiving side and receiving the channel information estimated by a signal included in the signal measurement region instructed by the instruction information from the receiving side.

Abstract: Methods, circuits, and systems for increasing bandwidth and/or transition separation in data communications and data storage in the presence of potential intersymbol interference (ISI). The method includes writing L bits of serial data per data transition period to a channel, reading data units from the channel M times per data transition period (M?L), and determining a most likely value for a K*2(L-M)-bit binary sequence of the data. The circuit generally receives m-ary symbols, converts them to n-ary data, and includes detector logic that (i) calculates a most likely n-ary data sequence from L-unit blocks thereof, and (ii) disallows subsequent L-unit blocks in which there is a transition and any of the first x units do not equal any of the last y units in an immediately preceding block (where x+y=L). Generally, successive transitions in the serial data are at least L/M bit lengths apart.

Abstract: A first grouping of memory space addresses is generated for systematic bits of a received codeword; a second grouping of memory space addresses is generated for a first set of coding bits of the received codeword, wherein the first set of coding bits comprises an ascending order; and a third grouping of memory space addresses is generated for a second set of coding bits of the received codeword, wherein the second set of coding bits comprises an interleaved order. A sub-codeword of the received codeword is decoded in parallel by accessing the first set of coding bits using the addresses in the second grouping of memory spaces. In turn, another sub-codeword of the received codeword is decoded in parallel by accessing the second set of coding bits using the addresses in the third grouping of memory spaces. Apparatus and a memory storing a computer program are also detailed.

Abstract: A partial response signaling system includes a transmitter circuit configured to equalize input data in response to a control signal and to transmit a partial response signal through a transmission medium; and a receiver circuit configured to recover an output data from the partial response signal and to generate the control signal based on the partial response signal and an expected signal to output the control signal to the transmitter circuit.

Abstract: Various aspects of a method for minimum mean square error soft interference cancellation (MMSE-SIC) based sub-optimal maximum likelihood (ML) detection for a multiple input multiple output (MIMO) wireless system may comprise selecting at least one constellation point in a constellation map based on at least one of a plurality of received symbols. A number of the at least one constellation point may be less than or equal to a number of previously selected constellation points in a previous constellation map. At least one of the plurality of received symbols may be decoded based on the selected at least one constellation point.

Abstract: A non-linear post-processor for estimating at least one source of signal-dependent noise is disclosed. The post processor may receive a set of preliminary decisions from a sub-optimal detector along with the sampled data signal. The post-processor may then compute the transition jitter and white noise associated with each preliminary decision in the set and assign a cost metric to each decision based on the total signal noise. The post-processor may output the decision with the lowest cost metric as the final decision of the detector.

Abstract: Techniques are provided for performing hierarchical coding in a multi-antenna communication system (e.g., a SIMO, MISO, or MIMO system). At a transmitter, a base stream and an enhancement stream are coded and modulated separately to obtain first and second data symbol streams, respectively. The first data symbol stream is processed in accordance with a first spatial processing scheme (e.g., a transmit diversity or a spatial multiplexing scheme) to obtain a first set of symbol substreams. The second data symbol stream is processed in accordance with a second spatial processing scheme (e.g., transmit diversity or spatial multiplexing) to obtain a second set of symbol substreams. The first set of symbol substreams is combined (e.g., using time division multiplexing or superposition) with the second set of symbol substreams to obtain multiple transmit symbol streams for transmission from multiple transmit antennas. A receiver performs complementary processing to recover the base stream and enhancement stream.

Abstract: Embodiments of the present invention provide a method, apparatus and system of decoding spatially multiplexed signals. In some demonstrative embodiments the method may include, for example, determining one or more hypothetical values of a transmitted signal of a set of transmitted signals based on one or more respective sets of hypothetical values assigned to a subset of the set of transmitted signals. Other embodiments are described and claimed.

Abstract: A demodulator recovers a transmitted symbol represented by a received quadrature amplitude modulation (QAM) signal. Such a demodulator may include: a QAM-decoding block operable to map a received signal vector onto a constellation so as to yield a first symbol, and identify a next-most probable second symbol based upon the signal vector; and a selection unit operable to select, among the first and second symbols, the one having the lower error content as corresponding to the transmitted symbol. A corresponding method may include similar steps.

Abstract: A pipelined decision feedback unit (DFU) is disclosed for use in reduced-state Viterbi detectors with local feedback. The disclosed pipelined decision feedback unit improves the maximum data rate that may be achieved by the reduced state Viterbi detector by the pipelined computation of partial intersymbol interference-based estimates. A pipelined decision feedback unit is thus disclosed that computes a plurality of partial intersymbol interference based estimates, wherein at least one partial intersymbol interference-based estimate is based on a selected partial intersymbol interference-based estimate; and selects the selected partial intersymbol interference-based estimate from among partial intersymbol interference-based estimates for path extensions into a state.

Abstract: A method of constructing an effective generator polynomial for error correction by which a unique set of syndromes for each error event is produced is provided. The method includes preparing a set of dominant error events from the intersymbol interference characteristics of media; and generating a codeword from the data using a non-primitive generator polynomial that produces a unique syndrome set which can completely specify each dominant error event.

Abstract: A decoder decodes a code by selecting, based on a predetermined condition, a path out of paths representing a transition of each of states in a trellis diagram. A storing unit stores, when a path at time k is selected, information on a selection history of a path selected at time prior to time (k?(a constraint length of a code)+1). A path detecting unit detects a path to be excluded from a path selection candidate, based on the information stored in the storing unit and information on a state of a transition source when a state transition occurs from time k?1 to time k.

Abstract: An improved Viterbi detector is disclosed in which each branch metric is calculated based on noise statistics that depend on the signal hypothesis corresponding to the branch. Also disclosed is a method of reducing the complexity of the branch metric calculations by clustering branches corresponding to signals with similar signal-dependent noise statistics. A feature of this architecture is that the branch metrics are clustered into multiple groups, where all the members of each group draw input from a single, shared noise predictive filter corresponding to the group. In recording technologies as practiced today, physical imperfections in the representation of recorded user data in the recording medium itself are becoming the dominate source of noise in the read back data. This noise is highly dependent on what was (intended to be) written in the medium. The disclosed Viterbi detector exploits this statistical dependence of the noise on the signal.

Abstract: A method of shaping an orthogonal frequency division multiplexing (OFDM) signal spectrum is disclosed. The method comprises receiving an input signal that has a frequency spectrum that includes a frequency peak, and limiting the amplitude of the frequency peak to a predetermined clip level. An orthogonal frequency division multiplexing (OFDM) transmitter is disclosed. The OFDM transmitter comprises an input interface configured to receive an input signal that includes a frequency spectrum that includes a frequency peak, and a processor coupled to the input interface, configured to limit the amplitude of the frequency peak to a predetermined clip level.

Abstract: A continuous time equalizer for equalizing an input signal using a feedforward equalizer portion and a feedback equalizer portion is provided that includes: a slicer operable to make bit decisions on a combined output from the feedforward and feedback equalizer portions; an adaptive delay circuit operable to delay the combined output to form a delayed output; and a controller operable to control the delay provided by the adaptive delay circuit such that a first group delay through the slicer and a second group delay through the adaptive delay circuit in response to a sinusoidal form of the input signal are substantially equal.

Abstract: A method of evaluating the quality of a read signal from the viewpoint of the detection margin of a Viterbi decoder in the PRML method in which a target signal level varies depending on the read signal, and an optical disc apparatus implementing the method. A method of evaluating the quality of a signal pattern comprising a combination of minimum run lengths from the viewpoint of edge shift, and an optical disc apparatus implementing the method. From the target signal level that varies depending on the read signal, a target signal is generated based on a decoding result, and an error target signal is generated in which the decoding result is edge-shifted. The signal quality is evaluated by calculating a Euclidean distance between these signals and the read signal.

Abstract: Embodiments of the invention provide techniques for optimizing the detector target polynomials in read/write channels to achieve the best error rate performance in recording devices. In one embodiment, a method of obtaining a detector target polynomial of a read/write channel to achieve best error rate performance in a recording device comprises: providing an initial detector target for the read/write channel; measuring a noise autocorrelation of the read/write channel at the output of equalizer using channel hardware; computing a noise autocorrelation at the output of the 1st stage target based on the measured noise autocorrelation of the read/write channel at the output of equalizer; calculating optimal coefficients for the noise whitening filter; and obtaining the optimal detector target polynomial of the read/write channel using the calculated coefficients for noise whitening filter.

Abstract: A reconfigurable partial response encoder manages the emitted spectrum of a digital signal.