Abstract: In a refractive index coupling distributed semiconductor laser having a ?/2-phase-shift distributed feedback structure with a diffraction grating having a refractive index coupling property on an active layer, when viewed in a light distributed feedback direction, a value of (duty of a high refractive index portion)/(duty of a low refractive index portion) of a diffraction grating in a rear end face region is larger than that of a diffraction grating in a front end face region. In this manner, a coupling coefficient ?2 in a front end face region of a conventional semiconductor laser is smaller than a coupling coefficient ?1 in a rear end face region and is larger than 100 cm?1.

Abstract: A helium purge for a grating based line narrowing device for minimizing thermal distortions in line narrowed lasers producing high energy laser beams at high repetition rates. Applicants have shown substantial improvement in performance with the use of helium purge as compared to prior art nitrogen purges. In preferred embodiments a stream of helium gas is directed across the face of the grating. In other embodiments the purge gas pressure is reduced to reduce the optical effects of the hot gas layer.

Abstract: Disclosed is a laser module case having a snout disposed within a wall of the case, wherein the snout may allow alignment of a laser with an optical fiber after closure of the case. The snout has an inner end, outer end and longitudinal hollow. An optical fiber assembly, also with an inner end, outer end and longitudinal hollow, is disposed within the snout hollow. An inner flange secures the snout to the optical fiber assembly at their inner ends and an outer flange secures the snout to the optical fiber assembly at their outer ends. The optical fiber assembly is of a smaller cross-sectional diameter than the snout hollow so that it may move in an X and Y-direction. The optical fiber assembly may be aligned with a laser positioned within the case after the case is closed. The aligned fiber assembly may then be secured in position by the outer flange.

Abstract: The disclosure details a method of measuring the quality of service of broadcast media signals by analyzing digital watermarks embedded in the received broadcast signal. This method enables the quality of the broadcast video or audio signal to be measured without having the original version of the signal before broadcast transmission. Instead, the method analyzes the strength or quality of the embedded digital watermark to determine the quality of the received broadcast signal. The degradation of a watermark signal is used to measure quality of service of broadcast signals, such as audio and video.

Abstract: Method of estimating the channel and the direction of arrival of a signal transmitted by a transmitter and received by an array of antennae after being propagated along at least one path, comprising, for each path, a first step of estimating phase differences (?l) in the signals received by the different antennae in the array, a second step of estimating the angle of arrival (?) of the signal as well as the phase rotation (?) undergone by the signal along the said path from the said phase differences and a third step of estimating the attenuation (?) undergone by the signal along the said path from the estimated values ({circumflex over (?)}, {circumflex over (?)}) of the phase rotation and the angle of arrival.

Abstract: A multi-user detection method and device for a receiver in a multi-carrier code division multiple access telecommunication system, each communication to or from a user of the system being coded with a signature, the signal received by said receiver being decomposed into a first plurality of frequency components The frequency components are subjected to a first filtering matched to the respective signatures of a second plurality of users and to the common or respective responses of the transmission channels associated to said communications to or from said users. The output of the first filtering is subjected to a forward filtering followed by an estimation of the symbols transmitted to or by the users. The estimated symbols are subjected to a backward filtering, the output of said backward filtering being subtracted from the output of the forward filtering prior to the estimation.

Abstract: An apparatus, such as a subscriber unit or a base station within a spread spectrum communication system, provides advanced control over the time-tracking of demodulation elements when unresolvable multipath situations arise. The apparatus provides merge protection that prevents clustered demodulation elements from contracting beyond a minimum time span. In addition, the apparatus provides a master/slave feature for synchronizing the time-tracking of the demodulation elements when clustered around a multipath signal.

Abstract: The invention provides a method and apparatus for estimating flat fading channel in CDMA communication system, said method is implemented by using an adaptive forward prediction technique based on lattice filter and maximum likelihood technique of Viterbi algorithm. The adaptive lattice filter is used to carry out prediction of LS criteria on channel fading, and a maximum likelihood detection technique completes Viterbi algorithm in accordance with a channel fading value obtained by the prediction, thus obtaining final estimation and decision about the transmitting signals. The present invention has the advantages that it can obtain accurate result for channel estimation and sequence decision when it operates in the fast fading channel, and overcome fast fading influence due to motion speed up of mobile station, thereby satisfying mobile station speed and corresponding receiving performance required in 3G mobile communication.

Abstract: In a method for parallel interference cancellation (PIC) in a mobile communication system, every user signal is processed through multiple stages of PIC to remove multiple address interference (MAI) partly. In any middle stage and final stage, multipath de-spread is made for output signal of last stage to obtain a multipath de-spread result of this stage. The multipath de-spread result of this stage and that of the last stage of a user are combined to obtain a combined multipath de-spread result, which is sent to next stage when it is in a middle stage. Channel estimation and multipath combination are made based on the combined multipath de-spread result to obtain an output of the user. A PIC device is provided for the method. The method and the PIC device may raise SNR of the de-spread result of each user.

Abstract: A technique for allocating fingers in a path searcher of a multipath receiver involves determining a required number of fingers for each multipath region, determining a number of allocated fingers for each multipath region according to an area-based weighting scheme such that each multipath region that is allocated fewer than its required number of fingers is deemed to have a non-zero residual area, allocating any surplus fingers to multipath regions having non-zero residual areas until either no surplus fingers remain or each multipath region is allocated its required number of fingers, and placing any fingers allocated to each multipath region within the multipath region. Placing the fingers in un-resolvable path scenario involves detecting path location at the edges of multipath region; placing fingers at the edges and placing remaining fingers uniformly between the first and the last path such that the there is a minimum placement separation between the fingers.

Abstract: A narrowband interference excision method and apparatus. According to one embodiment, a method for narrowband interference excision is disclosed. The method comprising transforming time domain data into a frequency domain vector having a plurality of frequency bins. The method further comprises estimating a plurality of power values corresponding to frequency bins of the frequency domain vector to obtain a current power vector. Then, calculating an average power vector from the current power vector and at least one selected previous power vector. Further, excising selected frequency bins of the frequency domain vector to produce an excised frequency domain vector. Moreover, determining whether to include the average power vector in future average power vector determinations. In another embodiment, a narrowband interference excision apparatus is disclosed.

Abstract: The invention relates to a method, a processing unit and a system for determining the correlation between samples of a received code modulated signal and samples of replica code sequences. In order to simplify and accelerate the process, it is proposed that the received samples and the replica samples are aligned to each other and that the positions of the samples in the received signal and in the replica code sequences are grouped, each group comprising all positions at which the composition of the values of the samples of all of the replica code sequences is similar. The values of the received samples which are associated to a respective group are combined separately for each group to obtain a respective preliminary result. Then, a correlation value is determined for each replica code sequence by combining the preliminary results obtained for all groups separately for each replica code sequence, taking into account the values of the samples of the replica sequences in the respective group.

Abstract: A method and system that communicates adaptive transmit-side filter updates between a receiver and transmitter inserts additional versions of control codes into a back channel for encoding updates. Since the control codes are required in the back channel, no additional bandwidth of the back channel is used to communicate the updates.

Abstract: In known methods for the transmission of data, the data transmission rate is reduced by bit errors especially at high carrier frequencies. In the new method, the data transmission rate can be significantly increased due to the increased reliability in the data transmission by means of the integration of a test signal.

Abstract: A series of digit processing units (DPUs) are connected to form a finite impulse response (FIR) filter. Each DPU includes a register, a multiplexer, and a coefficient multiplier. The register stores and delays an input digital signal to be filtered. The multiplexer has inputs connected to the input node and to an output of the register, an output of the multiplexer for connecting to a next stage DPU. The coefficient multiplier is connected to the output of the register and multiplies the input signal by a coefficient or part of a coefficient. A group of DPUs can have multiplexers set so that the register of each DPU stores the same part of the input signal for processing a single filter coefficient. An adder is provided to sum output of the DPUs and output a filtered signal. The critical path of the FIR filter is independent of coefficient number and precision.

Abstract: In one aspect, the present invention is directed to a technique of, and system for enhancing the performance of high-speed digital communications through a communications channel, for example a backplane. In this aspect of the present invention, a transmitter includes equalization circuitry to compensate for bandwidth limitations and reflections in high-speed digital communication systems. In one embodiment, the equalization circuitry is designed, programmed and/or configured to introduce intersymbol interference in order to improve the signal integrity in high-speed communications and enhance the operation and performance of such systems. In this regard, the equalization circuitry includes temporally overlapping leading and/or trailing taps (relative to the data (symbol) signal) to reduce, minimize, mitigate or effectively eliminate pre-cursor and/or post-cursor intersymbol interference due to, for example, bandwidth limitations and reflections in high-speed digital communication systems.

Abstract: A system for reducing the complexity of an adaptive decision feedback equalizer, for use in connection with a dual-mode QAM/VSB receiver system is disclosed. QAM and VSB symbols, which are expressed in two's compliment notation, include an extra bit required to compensate for a fixed offset term introduced by the two's compliment numbering system. A decision feedback equalizer includes a decision feedback filter section which operates on symbolic decisions represented by a wordlength which excludes the added bit representing the offset. The vestigal word is convolved with the decision feedback filter's coefficients, while a DC component, corresponding to the excluded bit, is convolved with the same coefficient values in a correction filter. The two values are summed to provide an ISI compensation signal at the input of a decision device such as a slicer. A DC component representing a pilot tone in VSB transmission systems also introduces a DC component, and additional bits, to a VSB wordlength.

Abstract: A method and apparatus for adaptive signal compression of unknown signals uses minimal power and bandwidth to transmit data. The method provides adaptive signal compression with minimal loss and distortion by extracting only information of interest and recreating the full signal. The method uses a single resolution filter bank for channelizing a data stream for transmission. The method removes unwanted or unneeded information before transmitting the data by using fidelity and user controls and detection capabilities. The method provides significant signal compression where signals are sparse in frequency, time, or both and does not rely on a priori knowledge of the signal. After transmission, the system generates a signal using the data received as well as filling in the non-transmitted portions of the signal by manipulating the transmitted data. The system then formats the signal into the original data stream using a reconstruction filter bank.

Abstract: A method and apparatus for rate control for a constant-bit-rate finite-buffer-size video encoder is described. Rate control is provided by adjusting the size of non-intra frames based on the size of intra frames. A sliding window approach is implemented to avoid excessive adjustment of non-intra frames located near the end of a group of pictures. A measurement of “power” based on a sum of absolute values of pixel values is used. The “power” measurement is used to adjust a global complexity value, which is used to adjust the sizes of frames. The global complexity value responds to scene changes. An embodiment of the invention calculates and uses L1 distances and pixel block complexities to provide rate control. An embodiment of the invention implements a number of bit predictor block. Predictions may be performed at a group-of-pictures level, at a picture level, and at a pixel block level. An embodiment of the invention resets a global complexity parameter when a scene change occurs.

Abstract: An image coding method and apparatus considering human visual characteristics are provided. The image coding method comprises (a) modeling image quality distribution of an input image in units of scenes such that the quality of an image input in units of scenes is gradually lowered from a region of interest to a background region, (b) determining a quantization parameter of each region constituting one scene according to the result of modeling of image quality distribution, (c) quantizing image data in accordance with the quantization parameter, and (d) coding entropy of the quantized image data.

Abstract: A method of content adaptive decoding involves receiving a bitstream encoded wherein video content is segmented into portions based on predefined classifications or models, such as action scenes, slow scenes, low or high detail scenes, and brightness of the scenes. Based on the segment classifications, each segment or portion is encoded with a different encoder chosen from a plurality of encoders. The chosen encoder is particularly suited to encoding the unique subject matter of the segment. The coded bit-stream for each segment includes information regarding which encoder was used to encode that segment. A matching decoder of a plurality of decoders is chosen using the information in the coded bitstream to decode each segment using a decoder suited for the classification or model of the segment on a generic decoder.

Abstract: Techniques and tools for performing fading compensation in video processing applications are described. For example, during encoding, a video encoder performs fading compensation using fading parameters comprising a scaling parameter and a shifting parameter on one or more reference images. During decoding, a video decoder performs corresponding fading compensation on the one or more reference images.

Abstract: A picture coding method for transmission on a channel at a low bit rate and with a high error rate, for example, a channel with a bit rate less than 100 kbit/s and an error rate greater than 10?6, or even 10?4. The method uses motion estimation coding and divides the picture into a plurality of segments made up of macroblocks. At least for an edge macroblock of a segment, a motion estimation vector is allowed to extend into an adjacent segment. This is particularly advantageous for macroblocks situated top right of the segment if scanning for motion vector estimation is from left to right and top to bottom. Errors caused by estimating motion vectors within segments are avoided and the propagation of coding errors caused by splitting the picture into segments is limited.

Abstract: An encoding data processing apparatus generates at least one water marked version of an original item of material formed by introducing one of a predetermined set of code words into a copy of the original material item. The apparatus has a bandwidth adaptation processor configured to adapt a bandwidth of the code word to at least part of a bandwidth of the original material item, and an encoder configured to combine the bandwidth adapted code word with a copy of the original material item. The probability of correctly detecting a code word is improved by combining the code word with a part of the bandwidth of the material item. As a result, if the material is transformed in some way the code word may still be detected.

Abstract: The method performs a two-dimensional discrete wavelet transform on an image. The image comprises a plurality of blocks of pixels. The method generates (340) a current output block of subband data corresponding to a current block. The current output block is generated before either a one-dimensional discrete wavelet row or column transformation of a next block of pixels is completed, using intermediate lifting values stored (310, 350) during the generation of a plurality of previous blocks of subband data.

Abstract: An apparatus for converting pulse code modulation (PCM) signals in a telecommunication system between two different modulation standards. In the apparatus, a channel selector generates a channel select signal for identifying at least one channel of the multiple channels containing input digital signals modulated by said one of said two different modulation standards. A first codec demodulates a signal on a channel designated by the channel select signal which is modulated by the first modulation standard, into an analog signal to be supplied to a second codec, which modulates the converted analog signal input into a digital signal using the second modulation standard. The reverse process is executed in a similar manner.

Abstract: An electrical isolation barrier for use in a Data Access Arrangement uses a high frequency (HF) transformer 24 to provide isolation. An input signal, which may be analog or digital, is connected to a modulator. The analog output of the modulator is connected to the input of the HF transformer. The output of the HF transformer is connected to the input of a demodulator. Simple amplitude modulation can be used in the modulator to modulate the input signal to the frequency range of operation of the HF transformer. A simple low pass filter may be incorporated in the demodulator to remove harmonic distortion caused by the HF transformer. The output signal of the demodulator is substantially the same as input signal.

Abstract: Radio resources are saved. The base station 101 determines a possibility of transmitting data to the terminal 102, and transmits the indicator indicating the possibility of transmitting the data to the terminal 102. The terminal 102 generates a mode request message for determining a coding rate and a modulation system at the base station 101, and sets a transmission frequency of the mode request message based on the indicator transmitted from the base station 101. Accordingly, the mode request message is transmitted from the terminal 102 to the base station 101 at the determined transmission frequency.

Abstract: A COFDM demodulator providing independent DQPSK symbol amplitude and phase equalization provides improved soft-symbol estimates by reducing the possibility of clipping in the differential demodulator, improving the tolerance of the differential demodulator to finite word length effects, correcting for phase drifting between adjacent subcarriers, and improving signal-to-noise ratio (SNR) calculation accuracy for maximal ratio combining applications. Separate acquisition and tracking modes for the amplitude and phase equalizers are provided that handle start-up, reacquisition, and steady-state operation of the demodulator.

Abstract: A method of quadrature amplitude modulation involving encoding phase differentially and amplitude absolutely, allowing for a high data rate and spectral efficiency in data transmission and other communication applications, and allowing for amplitude scaling to facilitate data recovery; amplitude scale tracking to track-out rapid and severe scale variations and facilitate successful demodulation and data retrieval; 2N power carrier recovery; incoherent demodulation where coherent carrier recovery is not possible or practical due to signal degradation; coherent demodulation; multipath equalization to equalize frequency dependent multipath; and demodulation filtering.

Abstract: A method and apparatus for data communication in a variety of communication systems using spread spectrum techniques and multilevel sequences in which distinct multilevel sequences used contain binary subsequences that interfere constructively such that synchronous cross-correlation values add constructively. By adding two subsequences from different sets, it is ensured that neither subsequence belongs to the same set. This, in combination with use of correlators, reduces complexity and facilitates increasing the order of a modulation scheme, thus enhancing the bandwidth efficiency.

Abstract: Device, systems, and methods to detect unknown transmission formats are provided. Viterbi metric values may be calculated for a plurality of possible format parameters for a transmission format. Format metric values may be calculated for a plurality of the calculated Viterbi metric values, and the calculated format metric values may be compared. Based on the comparison, a probable transmitted format from a set of possible formats may be determined.

Abstract: A system and method are provided for transitioning between modulation formats in adjacent transmit bursts. The system includes a modulation system having a data interface, first modulation circuitry operating according to a first modulation format, and second modulation circuitry operating according to a second modulation format. During a transition between a first transmit burst in the first modulation format and a second transmit burst in the second modulation format, the data interface receives a timing signal signifying a start of data for the second transmit burst. In response to the timing signal, the second modulation circuitry resets, and the data interface delays the data for the second transmit burst by a modulator delay time. By delaying the data for the second transmit burst, a glitch caused by resetting the second modulation circuitry arrives at the output of the second modulation circuitry prior to the data for the second transmit burst.

Abstract: In the code word mapping operation of a radio communication system, mapping patterns are provided for different S/N ratios, the code word bits produced from a coder are not equally assigned to multi-level modulation bits, but weighted according to the resistance of multi-level modulation bits to error before being assigned, and the mapping patterns are switched in accordance with S/N. Since the code word mapping method is updated so that the error rate can be always minimized according to the situations of a propagation path and S/N ratio, communication can be made with high communication quality.

Abstract: A method for processing an input burst signal comprising a first step for identifying an additive DC component and generating an output signal, which is representative for an estimated value of said DC component. The method further comprises a second step for detecting a predetermined signal portion from a plurality of possible signal portions included in the input burst signal and generating a control signal indicating the presence of the predetermined signal portion in the input burst signal. The method is characterized in that the first step and the second step are performed in parallel i.e. in a commonly defined time interval from a starting time of the burst.

Abstract: The invention relates to a method for processing a signal, in which method a sample set is formed and a set of absolute values is formed. The method includes A) arranging the elements of the absolute value set in the ascending order; B) setting a threshold value; C) determining the number of elements of a reference set to be formed; D) forming a reference set; E) computing a reference value by multiplying the mean or median of the reference set by the threshold value; F) comparing the greatest element of the reference set with the reference value; G) increasing the number of reference set elements; H) reiterating the preceding steps D to G until the predetermined ending condition is fulfilled; I) forming an accepted absolute value set and a sample set by deleting the greatest element from the reference set.

Abstract: A data receiving device is provided enabling a reduction in the time required for extracting a partial band signal, and capable of being easily made in a simple structure as an LSI device without requiring a plurality of analog circuits having the same characteristics. The data receiving device includes: a first sampler for sampling an in-phase signal I(t) at every predetermined sampling period and outputting the sampled in-phase signal; a second sampler for sampling a quadrature signal at every predetermined sampling period and outputting the sampled quadrature signal; a partial band extracting section structured by a complex filter for extracting partial band signals IBr, QBr from frequency components included in the sampled in-phase signal and the sampled quadrature signal; and first and second delay detection operating sections for performing a delay detecting process based on the partial band signals and outputting detection signals.

Abstract: A carrier recovery apparatus capable of detecting a phase error of modulation signal by a simple calculation, reducing the circuit scale, and improving the frequency capture characteristic and phase jitter characteristic is presented. This carrier recovery apparatus comprises a symbol estimating unit for estimating the transmitted symbol, a phase error detector for generating a normalized phase error signal on the basis of the estimated symbol and reception signal, a loop filter for filtering the phase error, and a numerical control oscillator controlled by the loop filter.

Abstract: An apparatus and method for synchronizing sampling frequencies of a receiver and a transmitter of a multi-carrier communication system is provided. The receiver includes an estimator for estimating a frequency offset by employing an additional angle rotation of a received signal in frequency domain. The apparatus includes a compensation loop filter for generating a first output in response to a frequency offset compensation, an adder for adding the estimated frequency offset and the first output to generate a second output, and a loop filter for generating frequency offset compensation according to the second output. The method repeatedly applies the apparatus to generate frequency offset compensation, and then feeds it back to an oscillator to compensate the sampling frequency of the receiver. The apparatus and method can also be applied to a communication system with a carrier frequency offset.

Abstract: A system for estimating the modulation index and frequency offset of a CPM signal. An estimator filters the received signal and utilizes a training sequence to determine the modulation index and frequency offset of the CPM signal. The estimator can also include a post-processing step to eliminate all or part of a bias that might be created by the estimator.

Abstract: A receiver receives a digital signal. The digital signal contains a frame of robust VSB data and ATSC data, and the digital signal further contains a map. The map contains information indicating a location of the robust VSB data and ATSC data in the frame. A decoder of the receiver decodes the digital signal. A processor of the receiver processes at least one of the robust VSB data and the ATSC data according to the location information contained in the map.

Abstract: An improved method and apparatus for Viterbi Algorithm calculations for maximum likelihood sequence estimators in communication receivers is disclosed. The calculations for the maximum likelihood sequence estimator, in accordance with the invention, utilizes a variant of the Viterbi algorithm developed by Ungerboeck in which the associated branch metric calculations for the trellis require the computation of a set of branch metric parameters. An embodiment of the present invention provides for an improved recursive method and apparatus for calculation of the branch metric parameters that reduces the number of processor clock cycles required per state metric calculation. This enables real time computation of the branch metric parameters during execution of the Viterbi Algorithm.

Abstract: A Viterbi decoder capable of supporting a variety of constraint lengths and any arbitrary number of coefficients of a given estimated transmission path and composed of special hardware of small circuit scale. In the Viterbi decoder of the present invention, a branch metric calculation section (101) calculates the branch metrics of all paths from the state of the previous time to the state at the present time, selects the most probable path from the paths arriving at respective states based on the branch metrics (101a) and path metrics (103a) and outputs path select signal (102a) and path metric (102b). Path metric storage section (103) outputs path metric (103a) to be input to ACS calculation section (102) when performing ACS calculating at the next time.

Abstract: A method is provided for decoding a turbo-code encoded signal in a receiver. According to the method, the signal is received from a transmission channel, and the signal is digitally turbo-code decoded. Additionally, a quality information representative of conditions of the channel state estimation is dynamically determined, and the quality information is dynamically compared with a predetermined criteria for defining good or bad estimation conditions. A Maximum-A-Posteriori algorithm in the logarithmic domain is dynamically selected for good estimation conditions, or an approximation of the Maximum-A-Posteriori algorithm in the logarithmic domain is dynamically selected for bad estimation conditions. Also provided is a receiver that implements such a decoding method.

Abstract: A receiver for use in a mobile communications network, the receiver comprising an input for receiving radio signals including control symbols and data symbols, a channel estimator arranged to use the control symbols to provide a channel estimate for correcting received data symbols, a first offset corrector for de-rotating the control symbols prior to their use in providing the channel estimate, a second offset corrector for rotating the channel estimate prior to its use in correcting the received data symbols, and an offset estimator arranged to generate estimates of frequency offset in the received radio signal, for use in the first and second offset correctors.

Abstract: An adaptation process for automatic gain control is adapted to obtains the statistical characteristics of the received signal to estimate the input signal power level. The estimated input signal power level is used to adjust the gain of a variable gain amplifier for the automatic gain control.

Abstract: An analog signal gain control circuit(ASGC) for a digital radio HomePlug orthogonal frequency division multiplexing (OFDM) receiver includes a digital variable gain amplifier (DVGA) to control the gain of a received signal to achieve a desired signal amplitude to match a dynamic range of an analog-to-digital converter (ADC), an inverse scaling stage controlled to inverse-scale the signal output by the ADC, and a two-stage fast attack and slow decay filter that outputs control signals to the DVGA and to the inverse scaling stage. The fast attack and slow decay filter rapidly responds to an increase in signal amplitude and slowly decays the amplitude of the control signal in response to a decrease in input signal amplitude.

Abstract: A device that transmits data using discrete multitone modulation includes a memory that stores intercarrier interference (ICI) information for each of the tones used to transmit data. The device also includes logic that receives signals transmitted from another device, estimates a noise value for each tone and adds the estimated noise to the ICI information to determine an effective noise value. The effective noise value may then be used to generate an effective signal-to-noise ratio (SNR). The effective SNR may then be used by a loading controller to determine bit loading information for each tone. The bit loading information may be transmitted to the other device, which may then use this information to identify the appropriate number of bits to load in each tone when transmitting data.

Abstract: System and method for reducing interference to existing devices. A preferred embodiment comprises specifying a frequency range for a set of dummy signals, specifying a clipping function to ensure that the set of dummy signals do not exceed a maximum power constraint, incorporating a least squares solution for computing the set of dummy signals into the clipping function, and iterating the clipping function until a terminating condition is reached. The use of the clipping function limits the magnitude of the dummy signals, to ensure that dummy signals do not exceed a maximum power constraint.

Abstract: The invention relates to a device for cancelling inter-symbol interference in a sampled digital signal. The device comprises a first filter, for which the optimum transfer function is identical to that of the transmission channel, and which receives a sequence of samples ({{tilde over (d)}n}n?N) representative of the digital signal sent to the input of the transmission channel, a subtractor circuit to subtract the first filter output ({{tilde over (d)}?n}n?N) from the sequence of input samples ({rn}n?N), a second filter tuned to the transmission channel, with an optimum transfer function H*(f), to which the output ({en}n?N) from the subtractor circuit is input, and an adder circuit designed to add the output from the second filter to the sequence of samples ({{tilde over (d)}n}n?N) representative of the digital signal sent to the input of the transmission channel, and thus generating a sequence of complex symbols ({n}n?N) without any inter-symbol interference.