Abstract: A device for scaling and quantization of digital soft output values (sk) from an equalizer has a control loop for controlling a statistical parameter (?) for the scaled and quantized soft output values (sD,k), which contains a calculation unit (4) for calculation of the statistical parameter (?), and a control unit (5) for calculation of a scaling factor (c) for scaling the soft output values (sk) from the equalizer on the basis of the statistical parameter (?).

Abstract: Methods and systems for reconfigurable soft-output bit demapping, reconfigurable for different modes of operation (i.e., different transmitter/receiver configurations) and for different modulation schemes are provided. In an embodiment, a reconfigurable soft-output bit demapping system includes a mode/modulation independent equalizer, a plurality of mode/modulation independent soft-slicers coupled to the outputs of the equalizer, a plurality of mode/modulation independent post-scalers coupled to the outputs of the soft-slicers, and a mode-dependent coefficient calculator. The coefficient calculator generates parameters for configuring the equalizer, the soft-slicers, and the post-scalers according to the used mode of operation and modulation scheme.

Abstract: The feedback of reinterleaved correctly decoded data blocks to a decoder is provided for use in channel decoding operations of channel coded word containing data block. Once a properly decoded data block has been determined, feedback of constraints on the estimated bit sequences decoded data characteristics to a turbo decoder assist in additional decoding operations. Estimated bit sequences may be selected from those trellises that pass through the constraint imposed by knowledge of re-interleaving properly decoded data blocks. This allows the decoder to generate solutions having a minimum probability of error that are also confined by the re-interleaved properly decoded data blocks.

Abstract: A signal converter having a memory bank and radix-2 Fast Fourier Transform (FFT) transforms an Orthogonal Frequency Division Multiplexing (OFDM) signal having a long preamble and data into an OFDM signal in the frequency domain, and outputs the transformed OFDM signal. The radix-2 FFT has a linear systolic array architecture, transforms the long preamble stored in the memory bank by FFT, then stores the transformed long preamble into the memory bank, transforms data input through a buffering process and data input directly by FFT, and stores the transformed data in the memory bank. The memory bank has four memories, stores the long preamble transformed or not transformed and outputs the stored long preambles or the transformed data for the purpose of demodulation as the transformed data is input. Data-processing delay and/or power consumption may be reduced during the operation of the FFT processor.

Abstract: Equalization circuitry may be implemented by cascading a plurality of equalization stages. Each equalization stage may compensate for some of the attenuation of a received data signal. Each equalization stage may also be configured to perform decision feedback equalization to remove distortion from the current bit of data signal caused by one of the preceding bits in the data signal. Each equalization stage may be controlled by a DFE coefficient that determines the amount of voltage with which to adjust the output of the equalization stage. The equalization circuitry may be implemented on a receiver that includes clock data recovery circuitry and a pipeline/deserializer for providing preceding bit values to the equalization stages.

Abstract: A communication system in which a signal is transferred includes a transmitter that transmits a signal, a receiver that receives a signal transmitted thereto, and an adaptive equalizer that generates a compensated signal by compensating degradation of the signal to be received by the receiver. The adaptive equalizer includes a signal compensating section that generates the compensated signal by passing therethrough the signal to be received by the receiver, a jitter measuring section that measures jitter of the compensated signal output from the signal compensating section, and an adjusting section that adjusts a characteristic of the signal compensating section so as to reduce the jitter of the compensated signal which is measured by the jitter measuring section.

Abstract: A receiver suppresses co-channel interference (CCI) from other transmitters and intersymbol interference (ISI) due to channel distortion using “virtual” antennas. The virtual antennas may be formed by (1) oversampling a received signal for each actual antenna at the receiver and/or (1) decomposing a sequence of complex-valued samples into a sequence of inphase samples and a sequence of quadrature samples. In one design, the receiver includes a pre-processor, an interference suppressor, and an equalizer. The pre-processor processes received samples for at least one actual antenna and generates at least two sequences of input samples for each actual antenna. The interference suppressor suppresses co-channel interference in the input sample sequences and provides at least one sequence of CCI-suppressed samples. The equalizer performs detection on the CCI-suppressed sample sequence(s) and provides detected bits. The interference suppressor and equalizer may be operated for one or multiple iterations.

Abstract: Equalizers are provided including an N-tap feed forward filter, an M-tap feed backward filter, an L-tap filter, a control unit and an accumulator. The control unit is configured to connect the L-tap filter to the N-tap feed forward filter or the M-tap feed backward filter based on multipath information present in a communications channel. The accumulator is configured to sum output signals from at least one of the N-tap feed forward filter, the M-tap feed backward filter and the L-tap filter and to output a summation result. Related digital receivers, methods and computer program products are also provided.

Abstract: A method for adjusting a signal includes applying compensation to a data signal to generate an output signal and sampling the output signal to generate data values and an error value, each data value comprising either a high value or a low value based on the sampling of the output signal, the error value indicating residue of the distortion based on the sampling of the output signal. The method further includes monitoring the output signal for a pattern of data values corresponding to one or more filter patterns, the filter patterns each comprising a pattern of data values pre-determined to occur substantially equally in data beginning with even data and in data beginning with odd data. The method also includes detecting a pattern of data values in the output signal matching one of the filter patterns and adjusting the compensation applied to the data signal based on the error value.

Abstract: An over-sampled sequence detector operates on sampled data and tracks the detection reliability of the sampled data. The detector separately analyzes sample sequences for different sampling phases and then picks a sample sequence that allows for the most reliable detection. For the different sampling phases, the detector inspects some amount of look-behind and look-ahead information in order to improve upon simple symbol-by-symbol detection. The over-sampled information is used to further improve detection performance.

Abstract: A communication apparatus includes a radio frequency (RF) circuit configured to operate on an RF signal, and a digital processing circuit that is coupled to the RF circuit. The digital processing circuit may operate in association with the RF circuit according to a time domain isolation technique. In addition, the digital processing circuit includes a scheduler that may schedule a channel equalization task for each of one or more respective receive time slots. The scheduler may also schedule a decode task to obtain slot allocation information for each of the one or more respective receive time slots.

Abstract: A method to determine bit error rate (BER) for a given channel of a communication system includes determining a first statistical representation of at least one deterministic source of noise for the given channel. A parametric statistical representation having parameters that model non-deterministic noise is defined for the given channel and values for the parameters of the parametric statistical representation are estimated to provide a second statistical representation for the non-deterministic noise based on at least one of measurements and simulations performed for the given channel. The BER of the given channel is estimated as a function of the first and second statistical representations.

Abstract: The invention concerns methods and apparatus for performing channel equalization in a direct-sequence spread spectrum communications system. The methods and apparatus of the present invention are particularly applicable in situations where communication occurs over a channel experiencing multipath interference associated with paths having significantly different lengths. The impulse response-delay profile of such a channel is typically sparse, that is, dominated by a relatively few and widely spaced taps or clusters of closely spaced taps. In one aspect, equalization filter coefficients are calculated based on a channel estimate derived from a single cluster of closely-spaced channel taps collectively having the greatest percentage of energy as indicated by the impulse response-delay profile.

Abstract: A receiver for receiving a signal transmitted through a transmission channel includes an equalizer and a first quality calculator that obtains a first quality value of the received signal. The equalizer includes a first channel estimation unit that estimates a first channel response of the transmission channel from the received signal using a first estimation scheme, and a second channel estimation unit that estimates a second channel response of the transmission channel from the received signal using the second estimation scheme. The equalizer equalizes the received signal using the first or second channel response and outputs the equalized signal. A portion of the second channel estimation unit halts depending on the first quality value.

Abstract: In accordance with the present invention, novel methods for adaptive receiver design and related parameter estimation techniques for efficient and non-coherent reception of ultrawideband signals are presented. Efficient estimation of maximum excess delay of the channel for enabling many useful adaptation techniques is additionally provided. Also, noise power estimation which significantly improves the performance of the receivers is presented.

Abstract: A technique for enhanced reconditioning equalizer filter chain for multi-carrier signals with different technologies is described. The input to a transmitter chain is modified by an enhanced reconditioning equalizer filter chain for multi-carrier signals with different technologies, prior to being applied to the transmitter. The enhanced reconditioning equalizer filter chain modifies and smoothen the amplitude of the signal. The new signal is reconditioned and smoothened and has lower Crest Factor. The input to the enhanced reconditioning equalizer filter chain for multi-carrier signals with different technologies could be a baseband, an intermediate frequency (IF) or radio frequency (RF) signal. When the signal is an IF or RF signal it needs to be down converted to baseband before applied to enhanced reconditioning equalizer filter chain. The enhanced reconditioning equalizer filter chain for multi-carrier signals with different technologies could be implemented in digital or analog domain.

Abstract: A reception circuit includes: an AD converter; an equalization circuit that equalizes an output of the AD converter; a determination circuit to which error information is input from the equalization circuit; and a controller that adjusts at least one of resolution and voltage range of the AD converter, in the circuit the determination circuit outputs a control signal to adjust at least one of resolution and voltage range to the controller based on the error information.

Abstract: A digital radio frequency memory (DFRM) which converts an incoming analog radio frequency signal to a fourteen bit digital signal allowing for digital signal processing and then retransmitted as an analog RF signal. The DFRM provides a time delay for RF signals by storing the signal. The DFRM also changes the signal frequency in the range of plus or minus 100,000 KHz which places a doppler on the signal. The signal phase is changed in a range of 0 to 359 degrees by the DFRM.

Abstract: The present invention is directed to a method for equalizing a radio frequency (RF) waveform in a communication system. The method includes generating a DDS waveform at a predetermined instantaneous frequency. A digital instantaneous frequency signal corresponding to the predetermined instantaneous frequency is provided. A predetermined digital scaling factor corresponding to the predetermined instantaneous frequency is retrieved. The DDS waveform is multiplied by the digital scaling factor to yield an equalized DDS waveform.

Abstract: In one embodiment of the present invention, a method for adjusting a signal includes receiving an input data signal. The method also includes applying an offset compensation to the input data signal to generate an output signal. The method further includes, using a clock signal, sampling the output signal to generate a plurality of data values and boundary values, each value comprising either a high value or a low value based on the sampling of the output signal. The method also includes detecting a transition in value between two successive data values and determining a sampled boundary value between the two successive data values. The method further includes, based at least on the high or low value of the boundary value, adjusting the offset compensation applied to the input data signal.

Abstract: In a fixed wireless access (FWA) communications system comprising an Access Point (501) and a plurality of Subscriber Units (502-1, 502-2 502-N) each Subscriber Unit transmits a concentration word when it wishes to obtain access to transmit data. Each Subscriber Unit (502) includes a linear precoder (517) which predistorts the contention word to compensate for the impulse response of the transmission channel between it and Access Point (501). The precoder (517) is optimized specifically for the contention word to be transmitted instead of for general data.

Abstract: An apparatus and method for a multiuser receiver in a CDMA communication system are provided. The apparatus includes a plurality of White Matched Filters (WMFs) for pulse shaping received user signals, considering Multiple Access Interference (MAI), and a filter for detecting output signals of the WMFs using a Minimum Mean Square Error (MMSE) scheme, and outputting bit estimation values of the respective users. A transfer function of the WMF is determined by: adding a power spectral density function of the MAI to a power spectral density of an Additive White Gaussian Noise (AWGN); and multiplying an inverse number of the added value by a transfer function (H*(w)) of a Conventional Matched Filter (CMF). Accordingly, the SNIR can be maximized and thus the BER performance may be improved, without additional information, by using the filter in which the power spectral density of the MAI is added to the AWGN and then multiplied by the CMF function.

Abstract: A circuit and method for evaluating serializer deserializer (SERDES) performance that is particularly advantageous when the SERDES has a decision feedback equalizer (DFE). In one embodiment, the circuit has a data processing path and an operational feedback loop coupled to said data processing path and containing an equalizer, perhaps a DFE. In that embodiment, the circuit includes an eye scanning circuit coupled to said data processing path but separate from said equalizer and configured to measure at least one dimension of an eye relative to which said equalizer is configured for operation without substantially affecting said operation.

Abstract: Methods and circuits are presented for providing equalization, including decision feedback equalization (DFE), to high data-rate signals. Half-rate delay-chain circuitry produces delayed samples of an input signal using two or more delay-chain circuits operating at a fraction of the input signal data-rate. Two delay-chain circuits operating at one-half the input signal data-rate may be used. More generally, n delay-chain circuits operating at 1/n the input signal data-rate may be used. Multiplexer circuitry combines the outputs of the delay-chain circuits to produce an output signal including samples of the input signal at the input signal data-rate. Duplicate path DFE circuitry includes two paths used to provide DFE equalization while reducing the load of the DFE circuitry on the circuitry that precedes it. A first path produces delayed samples of a DFE signal, while a second path produces the DFE output signal from the delayed samples.

Abstract: The present invention relates to a method and device for estimating a timing error and a frequency offset in the MIMO mobile communication system. In a system including a plurality of transmit antennas and a plurality of receive antennas, a predetermined preamble symbol is inserted into a frame to be transmitted by a transmitting device, and pseudo noise is multiplied to the preamble symbol, and result signal is transmitted through each transmit antenna. A receiving device receives the signal through each receive antenna, extracts a preamble symbol from the OFDM symbol, and multiplies local pseudo noise that corresponds to the pseudo noise used by the transmitting device and is shifted by the extracted preamble symbol. A timing error is estimated and compensated according to the correlation of the pseudo noise of the transmitting device and the local pseudo noise of the receiving device. A frequency offset is estimated and compensated according to the phase difference between the preamble symbols.

Abstract: A system and method of detecting the location and magnitude of multi-path echoes in a channel impulse response by going through the channel impulse magnitude response only once and detecting all the multi-path echoes, both location and magnitude, according to certain threshold criteria. The impulse magnitude response samples are processed on-the-fly (on demand) and do not require the storage of the entire channel impulse magnitude response which makes it ideal for ASIC implementation.

Abstract: A system includes a time-interleaved device. An equalizer effectively can apply different equalization to different interleaved channels. For convenience, these equalizers will be referred to as multi-channel equalizers. In one aspect, an apparatus includes an interleaved device having M interleaved channels, and a multi-channel equalizer coupled to the interleaved device. The multi-channel equalizer is capable of applying a different equalization to different interleaved channels, thus compensating for channel-dependent impairments.

Abstract: A system and method is provided to produce a flatter frequency response from an audio source that has a non-flat frequency response and, as such, has missing spectral content. The system and method achieves a flatter frequency response by characterizing the frequency response of the audio source based upon a reference input signal. This reference input signal is used to establish a reference frequency response, which is stored in a memory and used to select equalizer settings. The system restores missing spectral content by way of summing multiple input signals from the audio source. The system then normalizes the frequency response based on characterizations of the signal by utilizing equalizer settings from memory.

Abstract: A programmable logic device is provided with adaptive equalization circuitry that is programmable in one or more respects. Examples of the programmable aspects of the equalization circuitry are (1) the number of taps used, (2) whether integer or fractional spaced taps are used, (3) what starting values are used in the computation of coefficient values, (4) whether satisfactory coefficient values are computed only once or on an on-going basis, (5) whether an error signal is generated using a decision directed algorithm or using a training pattern, (6) what training pattern (if any) is used, and/or (7) the location of the sampling point in the bit period of the signal to be equalized.

Abstract: Channel Equalization of a digital TV is disclosed. In channel equalization for restoring an original signal from a digital TV reception signal having passed through a channel, the present invention includes estimating an impulse response of the channel from a received signal having passed through the channel using conjugate-gradient algorithm, finding an equalizer coefficient in a frequency domain using the estimated impulse response of the channel, outputting a signal equalized by multiplying a signal resulting from transforming the received signal into the frequency domain by the found equalizer coefficient, and predicting to remove an amplified noise of the equalized signal using the conjugate-gradient algorithm in a time domain. Accordingly, the variation of the channel impulse response according to time can be tracked in the dynamic channel having fast channel variation as well as the static channel, whereby equalizing performance can be enhanced.

Abstract: A device for processing streams is disclosed. The device includes a stream arranging unit which stacks and rearranges a stream, and a dummy inserting unit which inserts a dummy into the rearranged stream. The device may further include a convolutional interleaver which interleaves the stream with a dummy or an RS encoder and a CRC encoder.

Abstract: The invention relates to techniques for implementing high-speed precoders, such as Tomlinson-Harashima (TH) precoders. In one aspect of the invention, look-ahead techniques are utilized to pipeline a TH precoder, resulting in a high-speed TH precoder. These techniques may be applied to pipeline various types of TH precoders, such as Finite Impulse Response (FIR) precoders and Infinite Impulse Response (IIR) precoders. In another aspect of the invention, parallel processing multiple non-pipelined TH precoders results in a high-speed parallel TH precoder design. Utilization of high-speed TH precoders may enable network providers to for example, operate 10 Gigabit Ethernet with copper cable rather than fiber optic cable.

Abstract: The present invention provides an equalizer and a semiconductor device, that can suppress a decrease in S/N ratio of a reception signal, can facilitate a disconnection test by a direct current signal, and are excellent in reproducibility of a transmission signal. A low-pass filter receives a reception signal supplied from a reception end to output a signal obtained by removing a high frequency component from the reception signal. A subtraction unit subtracts an output signal from the low-pass filter from the reception signal. An addition unit adds the reception signal from the reception end to an output signal from the subtraction unit. Thus, an output signal from the addition unit has a frequency characteristic of emphasizing the high frequency component. Then, an amplifier amplifies the output signal from the addition unit to transmit it to an output end.

Abstract: A method and system of the present inventions reduces both near-end crosstalk (NEXT) and far-end crosstalk (FEXT) interferences due to handshake tones into upstream and downstream neighboring services, both at the customer premises equipment (CPE) and at the central office (CO), when handshake is experienced. An embodiment of the present inventions is directed to significantly reduce the NEXT and/or FEXT interferences due to handshake tones. For example, NEXT and/or FEXT interferences due to G.994.1 handshake tones, identified as, bins 7 and 9 for the Upstream channel and bins 12, 14 and 64 for the Downstream channel may be reduced. An embodiment of the present inventions provides an algorithm that may be used for both NEXT and FEXT Handshake Interferences reduction at the CO and at the CPE. In addition, the algorithm may operate in the time domain and in the frequency domain.

Abstract: Equalization circuitry may be used to compensate for the attenuation of a data signal caused by a transmission medium. The control circuitry for the equalization circuitry may generate control inputs for equalization stages that control the amount of gain provided to the data signal. A comparator may determine whether the gain from the equalization circuitry is less than or more than the desired amount of gain. A programmable up/down counter may adjust the counter value based on the output of the comparator. The counter value may be converted into one or more analog voltages using one or more digital-to-analog converters. These analog voltages may be provided to the equalization stages as control inputs. The control circuitry may also include hysteresis circuitry that prevents the counter value from being adjusted when the gain produced by the equalization stages is close to the desired amount of gain.

Abstract: By assigning a plurality of subcarriers 31 to a data channel 33 and assigning fewer subcarriers 32 than the plurality of subcarriers 31 to a control channel 34, and in addition locating the control channel 34 at the center frequency fc of a frequency band used to transmit the data channel 33, on the radio receiving apparatus side, the frequencies of a local signal by which the received signal is multiplied share the same value, thereby speeding up the switching between the control channel and the data channel.

Abstract: The present invention provides an equalizer and a semiconductor device, that can suppress a decrease in S/N ratio of a reception signal, can facilitate a disconnection test by a direct current signal, and are excellent in reproducibility of a transmission signal. A low-pass filter receives a reception signal supplied from a reception end to output a signal obtained by removing a high frequency component from the reception signal. A subtraction unit subtracts an output signal from the low-pass filter from the reception signal. An addition unit adds the reception signal from the reception end to an output signal from the subtraction unit. Thus, an output signal from the addition unit has a frequency characteristic of emphasizing the high frequency component. Then, an amplifier amplifies the output signal from the addition unit to transmit it to an output end.

Abstract: For a given channel and a filter having at least one filter tap, a set of at least one weight value is determined for the at least one filter tap according to which at least one weight value substantially minimizes a gradient of a frequency response for the given channel and substantially maximizes energy of the frequency response for the given channel within a predetermined bandwidth.

Abstract: An alternative approach to coping with the ever increasing demand for faster communications hardware is to design modems that are capable of operating its speeds at a higher data rate than a speed required for a single port of the standard communication rate for that modem. Basically, by utilizing a resource manager, that directs the data in and out of the various portions of the modem in an orderly manner, keeping track of which of the ports is being operated at any given point in time, a standard single port modem can be reconfigured, for example, at an over clocked rate, to manipulate the data input and output of a modem.

Abstract: A receiver for a multi-channel system such as a HDMI system is presented. In accordance with the present invention, the receiver receives one of the plurality of channels and includes an analog portion, a digital-to-analog converter, and a digital control block that provides digital control signals to the analog portion. Equalization can be accomplished partially or wholly in the analog domain and digitally controlled by a digital control loop. A digital equalizer can also be included. A decision feedback equalizer can be implemented that sums an analog output signal into the analog data stream. Timing recovery can be accomplished by digital control of a phase interpolator or delay locked loop that receives a plurality of phases from a timing circuit coupled to receive a clock signal.

Abstract: Various embodiments of the present invention provide systems and methods for performing data equalization. For example, various embodiments of the present invention provide data equalization circuits that include an equalization circuit and a transition adjustment circuit. The equalization circuit receives a series of at least two original data bits and replaces at least one of the two original data bits with an equalization pattern including two or more equalization bits. The original data bits correspond to an original data clock, and the two or more equalization bits correspond to an equalization data clock. The transition adjustment circuit is operable to modify an occurrence of a transition from one logic state to another logic state within the equalization pattern on a sub-equalization data clock basis.

Abstract: For eigenmode transmission with minimum mean square error (MMSE) receiver spatial processing, a transmitter performs spatial processing on NS data symbol streams with steering vectors to transmit the streams on NS spatial channels of a MIMO channel. The steering vectors are estimates of transmitter steering vectors required to orthogonalize the spatial channels. A receiver derives a spatial filter based on an MMSE criterion and with an estimate of the MIMO channel response and the steering vectors. The receiver (1) obtains NR received symbol streams from NR receive antennas, (2) performs spatial processing on the received symbol streams with the spatial filter to obtain NS filtered symbol streams, (3) performs signal scaling on the filtered symbol streams with a scaling matrix to obtain NS recovered symbol streams, and (4) processes the NS recovered symbol streams to obtain NS decoded data streams for the NS data streams sent by the transmitter.

Abstract: An equalization circuit that allows particularly for lowpass filtering by transmission lines comprises a compensating equalizer controlled according to whether the edges between bits in the data waveform are early or late. Adjusting the equalization causes edges to appear in the same place, whereas if the adjustment is incorrect certain edges will be late and certain edges will be early depending on the history of “1”s and “0”s in the data stream. This is an effect of so-called intersymbol interference. The control mechanism includes circuits for recognizing patterns of “1”s and “0”s in the recent history of the data waveform whose occurrence is used to trigger the adjustment of the equalizer.

Abstract: A receiving system and a method of processing broadcast signal are disclosed herein. The receiving system includes N number of antennae, N number of demodulators, N number of known sequence detectors, and an equalizer. The N number of antennae each receives a broadcast signal including mobile service data and known data sequences. The N number of demodulators demodulates the broadcast signal received by the corresponding antenna. The N number of known sequence detectors detects known data sequences from the broadcast signal received by the corresponding antenna.

Abstract: A method and apparatus for a feed forward equalizer for a communication system are described. An equalizer comprising a tapped filter having multiple filter multipliers and a summing element is described. The equalizer further comprises a correlator having multiple correlator multipliers, with each correlator multiplier having a corresponding integrator, a set of shared delay elements to connect to the filter multipliers and the correlator multipliers; and an error signal generator to connect to the correlator.

Abstract: A receiver and method for the same are provided. In the receiver, a decoder may decode an equalized signal to generate symbol decisions and a soft information signal. An equalizer may select boundary levels for non-uniform quantization using a soft information signal delayed by a symbol interval. The equalized signal may be generated from a feedback-filtered signal using the symbol decisions.

Abstract: Methods and systems for processing signals in a receiver are disclosed herein and may include generating a plurality of chip-rate synchronously sampled signals utilizing a plurality of received clusters. At least a portion of the generated plurality of chip-rate synchronously sampled signals may be simultaneously equalized in time domain and in spatial domain. The equalization may be based on a plurality of weight values calculated for the plurality of received clusters. The weight values may be iteratively computed utilizing a time-based adaptation method, such as a conjugate gradient (CG) search. The equalized portion of the generated plurality of chip-rate synchronously sampled signals may be added to generate a total equalized signal. The total equalized signal may be demodulated to generate a demodulated signal. At least one convolutional code and/or turbo code within the demodulated signal may be decoded.

Abstract: Method and process for receiving, demodulating, equalizing and processing of Modulation Demodulation Format Selectable (MFS) received signal, received from two or more than two antennas and from diversity receivers. Baseband processing filtering and adaptively equalizing demodulated signals and providing filtered equalized burst operated Time Division Multiplexed (TDM) cross-correlated in-phase and quadrature phase signal, spread spectrum Code Division Multiple Access (CDMA) signal and Orthogonal Frequency Division Multiplexed (OFDM) signals. Demodulation of peak limited cross-correlated OFDM signals. Demodulation and adaptive equalization of receive filtered signal, wherein the received filtered signal is mis-matched to transmit filtered signal. Process for receiving and demodulating MFS signals received from modulated linearly amplified and transmit filtered modulated non-linearly amplified (NLA) signal transmitters. Demodulation and processing of cross-correlated TDM, spread, spectrum and OFDM signals.

Abstract: An arrangement (100) and method for RF filtering in a Node B of a UMTS TDD system by providing: a DAC converter (130) converting digital signals to analog signals; providing a narrow band analogue channel filter (150) filtering the analog signals; and providing a digital pre-equaliser FIR filter (120) coupled before the DAC (120) to filter the digital signals, the digital pre-equaliser filter means substantially correcting for non linear phase response (122) non-ideality and amplitude response non-ideality (124) in the analogue channel filter (150). This provides the following advantage(s): it enables 3GPP Node B co-location specifications to be met while providing both good transmit accuracy and acceptable ISI performance; and it allows filter centre frequency to be field tuned in software, permitting a basic RF single-channel filter to used with its centre frequency being field adjustable to a desired value centred on a UMTS channel.

Abstract: The invention provides an ultra-wideband (UWB) transmitter and various techniques for generating digitally filtered UWB pulses that substantially maximize power and bandwidth in one or more frequency bands while allowing narrow-band interference (NBI) to be avoided, e.g. interference to and from wireless local area networks (WLANs). In particular, the UWB transmitter utilizes a digital filter to generate digitally filtered UWB pulses to substantially maximize power and bandwidth in the Federal Communications Commission (FCC) spectral mask for UWB communications. In one embodiment, the invention provides a method comprising generating digitally filtered ultra-wide band (UWB) pulses to substantially maximize power in one or more frequency bands of a UWB spectrum and to substantially reduce power in one or more NBI frequency bands of the UWB spectrum. The invention may be implemented without modifying the analog components of existing UWB transmitters.