Abstract: A software correlator comprising: a partitioning module adapted to divide a number of the received data samples into a first number of data blocks; a first correlation module adapted to correlate each of the data blocks with a respective local code replica segment to produce a first number of intermediate accumulation results; an aggregation module adapted to combine a number of consecutive results of the intermediate accumulation results into a target number of aggregated accumulation results, the target number expresses a number of discrete carrier values in a carrier vector that represents a Doppler shift of the at least one spread spectrum source signal relative to a downconverting frequency for this signal; and a second correlation module adapted to correlate the aggregated accumulation results with the carrier vector to produce the decoded signal, which is compensated for the Doppler shift relative to the downconverting frequency.

Abstract: A parametric form of G-Rake and chip equalization for closed-loop transmit diversity is provided, that accounts for impairment correlation between transmit antennas. In a closed-loop transmit diversity system, the base station transmits a signal from two or more antennas, using one of a predetermined set of relative phase offsets at one of the antennas. The parametric estimation of the impairment or data covariance is performed by summing terms, including a term for each possible phase offset. The terms are weighted by fitting parameters. The fitting parameters are jointly solved by fitting the impairment or data covariance estimate to a measured impairment or data covariance. In another aspect, a measured impairment covariance is formed by exploiting a special relationship between the pilot channels of the different transmit antennas.

Abstract: Calculating a diversity parameter adjustment includes accessing diversity parameter data generated from diversity parameter adjustments applied to a signal transmitted from a modifying communication device to a feedback communication device. The following are repeated. The signal is modified according to a current diversity parameter adjustment. Feedback describing the signal modified according to the current diversity parameter adjustment is received. The feedback describes the modified signal as received by the feedback communication device. A candidate diversity parameter adjustment is established in accordance with feedback. A most probable diversity parameter value is determined from the diversity parameter data, whether the candidate diversity parameter adjustment moves towards most probable diversity parameter value is determined. A next diversity parameter adjustment is established in accordance with the determination.

Abstract: A detector is provided for determining the carrier frequency of symmetrical, direct sequence, spread spectrum (DSSS) signals. The DSSS signal is divided between two signal paths, one path containing a frequency band inverter and the other a time delay unit. The outputs of the inverter and delay unit are connected to a multiplier and thence to a filter isolating the difference frequency of the inverted and non-inverted DSSS signals. The frequency inverter comprises an input band pass filter, a local oscillator, a second multiplier and a band pass filter. Frequency inversion is carried out by the multiplier and filter providing the difference signal between the local oscillator signal and the DSSS signal. The difference frequency provided by the filter is the known local oscillator frequency minus twice the DSSS carrier frequency.

Abstract: Embodiments of the present invention include techniques for performing cross correlations. In one embodiment the present invention includes a cross correlation system for use in a communication system comprising a wireless receiver receiving a signal including a first sequence of data values and converting the first sequence of data values into a sequence of digital data values, the wireless receiver further comprising a plurality of cross correlators that each receive the digital data values and cross correlate the digital data values with a corresponding plurality of different binary reference patterns, wherein if the first sequence of data values correlates with one of said plurality of binary reference patterns, one of said cross correlators generates a peak. In one embodiment, the cross correlators are partitioned into stages. In another embodiment, the received data values are loaded into a memory that is shared by the cross correlators to reduce hardware requirements.

Abstract: A method of processing a received first code-modulated signal, the received first code-modulated signal being a first signal modulated with a first code, to determine at least one of said first code and a delay in the first code-modulated signal, which determines a correlation between the received first code-modulated signal and a second code, the second code being at least substantially a sum of a plurality of further codes.

Abstract: A method is provided for frequency acquisition, particularly for initial frequency acquisition, pursuant to a known synchronization sequence for synchronizing a mobile communications device having a local oscillator with previously known transmit frequencies of a base station that transmit in a known channel raster with defined frequency points within a band, wherein the method includes the steps of determining the inband power of the known synchronization sequence via a sensor by scanning a frequency band, performing coarse determination of the local power maximum of the inband power and, thus, of the received carrier frequency over the scanned frequency band, producing a presumed channel frequency at which the base station is transmitting on the basis of knowledge of the channel raster of the transmit frequencies of the base station, performing fine determination of the received carrier frequency by comparison with the known synchronization sequence, and correcting the frequency deviation of the local oscil

Abstract: A human body communication system is provided. The human body communication system includes a transmitter and a receiver. The transmitter transmits a frame including a preamble, which is a Manchester-encoded pseudo noise (PN) code, to the human body. The receiver receives the frame from the human body, performs Manchester-decoding on the frame, performs cross-correlation on the decoding result and the PN code, and performs frame synchronization using the cross-correlation result. Accordingly, clock and data recovery performance is improved. Efficient frame synchronization with reduced computation amount can be provided.

Abstract: A de-correlating discriminating system of code division multiple access signals including a system structure composed of a plurality of cells, each of the plurality of cells including a base-station and a plurality of user-stations, each of the user-stations including a user-transmitter and a user-receiver, communicating through a multi-access channel with the base station which includes a base-station receiver and a base-station transmitter, and the user-transmitter is capable of transmitting a data symbol to convey a data with a spreading sequence and a pilot symbol that is the spreading sequence to identify a channel from the user transmitter to the base-station receiver and the base-station receiver includes a minimum means square error detector to analyze an input vector that is a received signal containing both multiple users specific data responses.

Abstract: A radio signal receiver in which a RF-receiving unit 12 converts a radio received signal to a baseband signal, an AD-conversion unit 15a, 15b converts that baseband received signal to a digital signal, and a baseband-processing unit 16 uses the digital signal to perform specified baseband processing, and in which an average-interference-level-measurement unit (SIR measurement unit) 17 measures the average interference level of the received signal, an amp-gain-adjustment unit 18 sets the gain so that a fixed binary value becomes that measured average interference level, and a variable-gain amp 14a, 14b controls the reception level of the received signal by that set gain.

Abstract: Methods and apparatuses for establishing time at a first basestation, and synchronizing the first basestation with other basestations in a cellular network. The method may be performed using a mobile (cellular communication) station that includes a satellite position system receiver. One method comprises determining a location of the mobile station, determining a time indicator that represents a time-of-day at the mobile station, wherein the time indicator is determined relative to a signal available at the first basestation, transmitting at least one of the position information and location, and transmitting the time indicator from the mobile station. The time indicator and at least one of the position information and the location are used to establish a time at the first basestation such that the first basestation is synchronized to other basestations in the cellular communication system. Other methods and apparatuses are also described for synchronizing basestations in a cellular network.

Abstract: A CDMA communication system uses a RAKE receiver, a code correlator and a multi-code joint detector to jointly detect symbols in two or more received signals contained within a composite signal. The RAKE receiver separates the composite signal into two or more RAKE output signals by despreading the composite signal using selected spreading codes. The multi-code joint detector jointly detects the symbols in the received signals using the RAKE receiver output signals, cross-correlations between the spreading codes generated by the code correlator, and RAKE combining weights based on a noise covariance matrix. The multi-code joint detector also includes a trellis that represents possible states and state transitions and a branch metric calculator for calculating branch metrics associated with the state transitions based on the RAKE receiver output signals and the cross-correlations between the spreading codes.

Abstract: Frame synchronization methods and systems suited for packet communications systems, and particularly time frequency hopping packet communication systems, are disclosed. Frame synchronization is performed by performing a first correlation on information of received symbols and performing a second correlation on results of the first correlation. In systems with repeating synchronization information modulated by a cover sequence, the results of the second correlation may be used to determine symbol numbering of symbols in a packet.

Abstract: A transmitter has a portion that sets a parameter about the transmitter itself based on a parameter made to correspond to a condition for selecting a receiver with which the transmitter communicate with, a portion that generates a spread code based on the set parameter, and a sending portion that spreads transmit-data to form a spread signal by the generated spread code, and that sends the spread signal. The receiver has a portion that receives the signal transmitted by the transmitter, a portion that sets a parameter about the receiver itself based on the parameter made to correspond to the condition, a portion that generates a despread code based on the set parameter, a portion that performs a correlation computation of the received signal and the generated despread code, and a portion that selects a transmitter with which the receiver communicates, based on a result of the correlation computation.

Abstract: In a method for reducing the dynamic range of a multicarrier transmission signal (12?) which is formed in a transmitter and is composed of two or more carriers, the various signal structure timings of the carriers are determined. A delay unit (100; D0, D1, . . . , DN-1) is then used to set a delay profile between the signal structure timings of various carriers, in such a manner that the signal structures of different carriers or substructures of them are not aligned in time with respect to one another.

Abstract: Synchronization techniques for reducing the effects of time dispersive wireless communications channels are presented. A synchronization technique for communications over a time dispersive wireless channel includes receiving a signal having at least identical first and second symbols, and calculating a metric for each sampling time by correlating respective samples of the first symbol included in a first sampling window with respective samples of the second symbol included in a second sampling window. The technique further includes identifying one of the sampling times at which the metric attains a maximum value, and estimating an optimal time offset for synchronizing to the received signal based on the identified sampling time. Optionally, the technique further includes estimating a carrier frequency offset based on the difference of phase of the complex conjugate samples at the maximum absolute value of the metric.

Abstract: A method for monitoring a redundant (passive) transmitter, being, for example, part of a base station of a point-to-multipoint radio communications system transmits, during normal operation, a spread-spectrum signal over the redundant transmitter, the spread-spectrum signal being of low spectral power in comparison with data signals being transmitted by the active transmitter of the base station. One or more receivers are associated, for example, with terminal stations in communication with the base station and detect the presence of the spread-spectrum signal. If the spread-spectrum signal is not found to be present, the receivers provide an indication of this, and from this indication, a decision is made as to the integrity of the redundant transmitter.

Abstract: The present invention comprises systems, methods, and devices for detecting the presence of a specified signal type by autocorrelating the signal with a time-delayed copy of itself, by simultaneously crosscorrelating the signal with an expected signal type, and by then comparing the results of the autocorrelation and crosscorrelation to determine whether or not the signal is present and to ascertain its type.

Abstract: A method and apparatus for performing frequency analysis of sub-epoch correlations to estimate an unknown frequency of a received signal is provided. The method includes forming a sequence of correlation values from a plurality of correlations performed over a period less than a repeating period of a code, and analyzing the sequence of correlation values to estimate the frequency that is used to receive a signal comprising the code.

Abstract: Complex digital data values derived from a DSSS signal, in particular, a GNSS signal, are delivered to a general purpose microprocessor at a rate of 8 MHz and chip sums over eight consecutive data values spaced by a sampling length (TS), each beginning with one of the data values as an initial value, formed and stored. For code removal, each of a series of chip sums covering a correlation interval of 1 ms and each essentially coinciding with a chip interval of fixed chip length (TC), where a value of a basic function (bm) reflecting a PRN basic sequence of a satellite assumes a correlation value (Bm), is multiplied by the latter and the products added up over a partial correlation interval to form a partial correlation sum. The partial correlation interval is chosen in such a way that it essentially coincides with a corresponding Doppler interval having a Doppler length (TD) where a frequency function used for tentative Doppler shift compensation and represented by a step function (sine, cosine) is constant.

Abstract: An apparatus for determining multipath correlations among a search range of input data, and a method thereof. The multipath searcher comprises a pseudo noise (PN) code generator, a correlator, and a data combiner. The PN code generator generates a first PN code corresponding to a first multipath component of the input data, postpones a first period based on the search range, then generates a second PN code corresponding to a second multipath component of the input data. The correlator is coupled to the PN code generator, and correlates the input data with the first PN code and the second PN code to produce a first correlation and a second correlation. The data combiner is coupled to the correlator, receives the first and the second correlations to determine a primary multipath component with a higher correlation thereto.

Abstract: A method and a device of providing timing information within a wireless communication system is described. The timing information is extracted from a received transmit signal. The inventive method comprises the steps of providing a training signal on the receiver side relating to a known signal portion of the transmit signal, scaling the training signal, quantizing the scaled training signal, correlating one or more parts of the received transmit signal with the scaled training signal to obtain one or more correlation results, and determining the timing information on the basis of the correlation results.

Abstract: Disclosed is a circuit for decoding code phase modulated (CPM) signals, including a pseudo-noise (PN) code storage device, storing one or more reference PN codes, a peak detector having an output with decoded CPM data, and a correlation block, including a correlation multiplexer, a plurality of shift registers coupled to the correlation multiplexer, a selection circuit coupled to the plurality of shift registers, and a correlator coupled to the code storage device and correlation multiplexer. Also disclosed is a method for operating the circuit in two operating modes for decoding CPM signals.

Abstract: A method for operating a Radio Frequency (RF) receiver of a wireless terminal. During a first time interval, an RF front end is enabled and the RF receiver receives and processes an RF signal, e.g., a Wideband Code Division Multiple Access (WCDMA) signal, to produce a baseband signal and to store samples of the baseband signal. During a second time interval that differs from the first time interval, the RF front end is disabled and the RF receiver processes the plurality of samples of the baseband signal of the first time interval to measure signal strengths of a plurality of pilot signals present in the baseband signal of the first time interval. Finally, during a third time interval that differs from the first time interval and the second time interval, the RF front end is enabled and the RF receiver receives and processes an RF signal of the third time interval to extract data there from. Memory is shared between the first, second, and third time intervals for different uses.

Abstract: A device (10) for preamble detection and frame synchronization, wherein data packets are transmitted by radio between transmitter and receiver and the data packets are in each case preceded by a known preamble with a sequence of preamble sections (B), with a correlator unit (20) for correlating samples (rn) with a preamble section (B), an accumulator unit (23) for accumulating correlation results, and a detector unit (24) for detecting a received preamble by a comparison of the accumulation result with a threshold value.

Abstract: Processing in a baseband processor is improved by estimating channelization code powers when processing received signals and reducing at least one of interference and noise power from the code power estimates. According to one embodiment of a wireless communication device such as a mobile phone or Local Area Network (LAN) adapter, the device comprises circuitry configured to receive a composite signal having contributions from a signal of interest and one or more interfering signals and a baseband processor. The baseband processor is configured to estimate channelization code powers for a channelization code associated with the signal of interest and one or more channelization codes associated with the one or more interfering signals. The baseband processor is also configured to reduce at least one of interference and noise power from the channelization code power estimates.

Abstract: The present invention provides a packet detector for use with a packet-based wireless receiver employing a receive antenna for P concurrently transmitted streams, where P is at least two. In one embodiment, the packet detector includes a correlation unit coupled to the single receive antenna and configured to provide a correlation function based on P acquisition fields corresponding to the P concurrently transmitted streams. Additionally, the packet detector also includes a pseudo-magnitude calculator coupled to the correlation unit and configured to calculate a packet detection metric based on the correlation function.

Abstract: A method of generating a code sequence in a wireless communication system is disclosed. More specifically, the method includes recognizing a desired length of the code sequence, generating a code sequence having a length different from the desired length, and modifying the length of the generated code sequence to equal the desired length. Here, the step of modifying includes discarding at least one element of the generated code sequence or inserting at least one null element to the generated code sequence.

Abstract: A bit synchronization method and system for a GPS, which receives a satellite signal sent by a satellite to accordingly produce a synchronous signal. Each data bit of the satellite signal consists of N CA-codes. A data buffer receives and stores the data bits of the satellite signal. A matched filter filters the N CA-codes of each data bit in order to compute correlations of the N CA-codes of each data bit, and accordingly output a correlation set corresponding to the data bit, wherein the correlation set has N correlations. A selector selects one with the greatest value from the N correlations and uses the CA-code corresponding to the one with the greatest value as the synchronization signal.

Abstract: A method of determining the location of a communication tag in a random phase multiple access communication network is disclosed. A ranging request signal that is spread using a first pseudo-noise code and offset with a first random timing offset is transmitted at a first time. A ranging response signal that is spread using a second pseudo-noise code and offset with a second random timing offset is received at a second time. A propagation delay that is dependent on the first time and the second time is calculated.

Abstract: A pre-correlation filter determines the timing of a second pseudorandom number (“PRN”) code, using an image of the average chip shape formed for a first PRN code. The filter collects measurements corresponding to samples of a received signal over multiple code chips of the first PRN code at sample times that are asynchronous to code rate. A code phase decoder directs the measurements to accumulation registers that are associated with code chip ranges that are fractions of a code chip of the first PRN code based on the code phase angles of the samples in the first PRN code, to accumulate measurements relating to chip transitions in the first PRN code and measurements relating to chip transitions in the second PRN code. The chip edges of the second PRN code are detected from the image of average chip shape for the first PRN code formed from the accumulated measurements.

Abstract: A GPS receiver architecture is disclosed having digital correlation processing in faster than real-time, which is achieved by storing signal samples into a memory in real-time at a first rate and reading packs of stored samples at a second higher rate. For mitigating cross-correlation interference from the strong signal to reception of weak ones, a group of compensator blocks is introduced. A method of interference waveform reproducing is disclosed that compensates influence of stronger signal over long coherent accumulation intervals, not complicating processing of the strong signal over shorter coherent accumulation intervals. Search bins corrupted by under-compensated interference are pre-calculated and discarded.

Abstract: Detecting Null symbols in a video data frame comprises sending OFDM symbols through a sliding windowed correlation process having a correlation window length proportional to a cyclic prefix length and a delay equal to a FFT size of the symbols, wherein output peaks of the process occur where two similar portions of the symbols coincide; checking peaks in windows sized equal to a duration of a symbol; determining whether the peaks are located in the middle of the windows; determining whether a shift has occurred in the location of the peak of a current window compared to in a second immediately previous window; determining whether the peak in a first immediately previous window is weak compared to that in a second immediately previous window; and declaring that a Null symbol exists in the first previous window when the shift has occurred and the determination of a weak peak exists.

Abstract: Methods and apparatuses for generating an OVSF code are disclosed. A proposed method for generating a current code chip of an OVSF code includes: determining a correlation factor between the current code chip and a preceding code chip of the OVSF code; and generating the current code chip according to the preceding code chip and the correlation factor.

Abstract: Multipath components of signals transmitted through time-varying digital radio channels are received with individual delays, and signals through a given channel comprise a code identifying that channel. A delay profile indicating a magnitude (Y) for delay values in a search window is calculated repetitively for known channels; the delays of multipath components for known channels estimated; a signal strength indicator calculated; and a search for new multipath components not already estimated performed at regular time intervals. When a new multipath component is found, its identification code is compared to the codes of the known channels. If the code of the new component is identical to the code of a known channel, a delay profile and a signal strength indicator is calculated for a window transposed to include the new multipath component. In this way as many multipath components as possible are included in the search window for a new cell.

Abstract: Disclosed is a correlation method to adaptively operate in a time varying phase and a correlator thereof. A correlation method according to the present invention includes performing the first correlation according to a certain reference value and a certain reference interval for correlation of a received signal; calculating an average variation of the received signal through the result of performing the first correlation; deciding a new reference value for the second correlation through the average variation; performing the second correlation according to the new reference value and the reference interval; and selecting the maximum value among the result of performing the second correlation. Accordingly, plural references are decided considering variation of a response signal between tags and also separate plural references are decided considering bit variation of a response signal in the same tag, so that a digital signal can be ideally demodulated in the environment where signal phase variation occurs.

Abstract: A method of recovering data for use in a receiver that simultaneously receives a plurality of code division multiple access data signals, each data signal experiencing a similar channel response. A combined signal over the shared spectrum in a time slot is received and sampled. The combined signal comprises the plurality of data signals. The sampled signal is used to estimate the similar channel response, and a channel response matrix is constructed. A channel correlation matrix is constructed based in part on the estimated channel response matrix. A fast Fourier transform (FFT) decomposition of a circulant matrix approximation of the channel correlation matrix, and the sampled data signals, are used to determine a spread data vector. The spread data vector is despread to recover data from the matrix.

Abstract: A method including correlating a code having a first offset with a signal to produce a first correlation result; correlating the code having a second offset with the signal to produce a second correlation result; determining a cost function using the first correlation result and the second correlation result; and adjusting the first offset and the second offset in dependence upon the cost function, wherein the cost function uses a first weighting for the first correlation result and a second, different weighting for the second correlation result.

Abstract: Implementation of an improved matched filter system for despreading a PN code from a spread spectrum signal utilizes a matched filter system that may be broadly conceptualized as a system that optimizes the number of multipliers and adders utilized by the system in despreading a PN code from a spread spectrum signal. This lowers the power consumption of the improved matched filter system and increases the speed at which the system despreads the PN code from the spread spectrum signal.

Abstract: In a synchronous acquisition method of a spread spectrum code, a digital code sequence is generated based on a received radio communication signal. The digital code sequence defines a spread spectrum code which includes a preamble symbol. A plurality of correlation signals are generated based on the spread spectrum code of the digital code sequence. A detection signal is generated in accordance with the correlation signal which corresponds to the preamble symbol. A timing control signal is generated in accordance with the detection signal. A demodulation signal is generated based on the correlation signals and in accordance with the timing control signal. A correction signal is generated based on the demodulation signal. A corrected timing control signal is generated based on the timing control signal and the correction signal, such that the demodulation signal corresponds to the preamble symbol.

Abstract: The present invention provides a method and system for operating a wireless communication system in which received signals from a plurality of antennas are weighted and combined with a beam forming operation to form an output signal. In an embodiment of the present invention, beamforming operations are performed with maximal ratio combining (MRC) and an interference nulling algorithm (INA). The INA receives an error signal which is 180° out of phase with a combination of the channels for individual antennas, referred to as the SUM channel. The error signal is determined by complex conjugate multiplication of the individual signals and a reference complex signal. The weight amplitude is controlled by weight normalization to provide faster convergence and prevent integrator overflow.

Abstract: A solution for determining in a radio receiver a data sequence indicating transmission parameters of a frame before receiving the whole frame in the radio receiver in order to speed up processing of the data in the frame. According to the provided solution data is received in one or more time intervals, the data being part of a transmitted data sequence indicating transmission parameters of a frame. The possible data sequences are known to the radio receiver. The received data is compared with corresponding data of each known data sequence, and, on the basis of the comparison, the data sequence which is determined to be closest to the received data is selected. The transmission parameters of the frame are determined based on the selection.

Abstract: The present invention concerns methods and apparatus for use in a spread spectrum communications system. In particular, in a method of the present invention information useful for acquiring a target signal is selected; the information is incorporated in an acquisition signal; the acquisition signal is transmitted; the target signal is spread with a spreading code; and the target signal is transmitted. At a receiving node, the acquisition information useful for acquiring the target signal is recovered from the acquisition signal and used to acquire the target signal. Apparatus in accordance with the present invention implement methods of the present invention. The methods and apparatus of the present invention can be used in node- and network-discovery situations.

Abstract: A chaos spreading code c(n) is inputted to a spreading unit 32. Data D1 and c(n) are multiplied in the spreading unit 32. A chaos spreading code d(n) is inputted to a spreading unit 42. Data D2 and d(n) are multiplied in the spreading unit 42. The chaos spreading codes c(n) and d(n) orthogonally cross each other. Outputs of the spreading units 32 and 42 are added by an adder 35 and transmitted through a transmitting unit 36 to a transmission path 38. By making an initial value which is set in a chaos sequence generator having a construction of a digital circuit different, the chaos spreading codes which orthogonally cross can be formed. Since the chaos spreading codes c(n) and d(n) orthogonally cross, an orthogonal modulating unit having a construction of an analog circuit for amplitude-modulating carriers which orthogonally cross can be made unnecessary and the construction can be simplified.

Abstract: A timing synchronization detects a temporary timing in a manner such that the presence of a first known signal in the received packet signal is detected by performing correlation processing on the first known signal in the received packet signal. The timing synchronization detects a timing in a manner that when the presence of a second known signal is detected, correlation processing is performed on the second known signal in the received packet signal. In the timing synchronization unit, a correlator is commonly used to perform two correlation processings.

Abstract: An apparatus for calculating decision parameters in an IMT-2000 system includes a correlation value calculation unit having a number of correlation value calculators, each of which calculates a correlation value between selected information that is selected at the mini-slot selection unit and one of capable input signals. To selectively operate the correlation value calculators, a ranking determination unit is included to receive and rank the correlation values and to selectively operating the correlation value calculators according to the rank of the correlation values. Accordingly, the power consumption of the correlation value calculators is reduced. And, the decision parameter is selected from the decision parameters previously selected during the divided monitoring section, thereby enabling high-speed cell search.

Abstract: A system for processing radio frequency (RF) signals includes a searcher and a plurality of Cluster Path Processor (CPPs). The searcher detects a maximum signal energy level and position of at least one of a plurality of individual distinct path signals in a signal cluster of a first information signal, wherein at least a portion of the plurality of individual distinct path signals is received within a duration of a corresponding delay spread. The sampling position is used as a starting sampling location by the plurality of CPPs, including a first information signal CPP and a second information signal CPP. Fine sampling positions of the plurality of CPPs are based upon channel energy estimates for the plurality of individual distinct path signals. CPP outputs are employed to produce channel estimates, which are themselves used in subsequent equalization operations. Sampling positions may change over time in order to satisfy alignment criteria.

Abstract: There is provided a hybrid rake/equalizer receiver for correlating a delay spread in a spread spectrum system. The hybrid rake/equalizer receiver includes a plurality of adaptive equalizers, each for filtering different regions of the delay spread that have an energy level above a pre-specified threshold to respectively provide equalized-descrambled chip sequences for correlation. Equalizer coefficients respectively corresponding to the plurality of adaptive equalizers are updated individually.

Abstract: A wired spread spectrum communication device, a method for communication thereof and a wired spread spectrum communication system capable of enabling easy establishment of synchronism are disclosed. In a transmitter unit of the wired spread spectrum communication device, a spreading code generator generates spread spectrum signals that are based on specified spreading codes, a strobe signal generator and a timing gate output the spread spectrum signals as sync signals at specified timings, and an adder superposes the sync signals to the spread information signals, while the adder further sends the information signals that have been superposed with the sync signals as transmitting signals to transmission paths.

Abstract: Demodulator architectures for processing a received signal in a wireless communications system. The demodulator includes a number of correlators coupled to a combiner. Each correlator typically receives and despreads input samples (which are generated from the received signal) with a respective despreading sequence to provide despread samples. Each correlator then decovers the despread samples to provide decovered “half-symbols” and further demodulates the decovered half-symbols with pilot estimates to generate correlated symbols. The decovering is performed with a Walsh symbol having a length (T) that is half the length (2T) of a Walsh symbol used to cover the data symbols in the transmitted signal. The combiner selectively combines correlated symbols from the assigned correlators to provide demodulated symbols. One or more correlators can be assigned to process one or more instances of each transmitted signal.