Abstract: Embodiments of the present invention provide a system and method for further reducing cyclostationarity and correspondingly energy density in a chaotic spread spectrum data communication channel, by digitally generating a first chaotic sequence of values to form a spreading code. The spreading code is then used to form a digital IF spread spectrum signal having a uniform sampling interval. The digital IF spread spectrum signal is converted to a sampled analog IF spread spectrum signal at a conversion rate substantially equal to the uniform sampling interval. The duration of the sampling interval is then selectively varied in accordance with a first pseudo-random sequence, thereby introducing a known dither in the analog IF spread spectrum signal. After introducing the known dither, the analog IF spread spectrum signal is upconverted to an analog RF spread spectrum signal. The first pseudo-random sequences may be designed to be a chaotic sequence.

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: The frame words of the embodiments are suitable for frame synchronization and/or channel estimation. By adding the autocorrelation and/or cross-correlation functions of frame words, double maximum values equal in magnitude and opposite polarity at zero and middle shifts are obtained. This property can be used to slot-by-slot, double-check frame synchronization timing, single frame synchronization and/or channel estimation and allows reduction of the synchronization search time. Further, the present invention allows a simpler construction of a correlator circuit for a receiver. A frame synchronization apparatus and method using an optimal pilot pattern is used in a wide band code division multiple Access (W-CDMA) next generation mobile communication system.

Abstract: In a method for estimating a frequency deviation between a received spread-spectrum code signal and a local frequency signal, the received spread-spectrum code signal is despread using a local spread-spectrum code. The despread signal is integrated over a particular integration period. From at least two successively obtained integration values, a phase change value characteristic of the phase change between the two integration values is calculated. From this, the frequency deviation is determined.

Abstract: The present invention relates to a receiver for receiving a spread spectrum modulated signal, comprising a sampler for forming samples of a received signal, at least one reference code block for generating at least first and second reference codes, and a correlation block. The correlation block forms first and second reference code parts from at least one reference code, and correlates the first reference code part with the sample string to form first correlation part results, and correlates the second reference code part with the sample string to form second correlation part results, wherein the correlations are arranged to be performed at different times and by using the same sample string. The invention also relates to an electronic device comprising a receiver, a module to be used with a receiver, a system comprising a transmitter and a receiver for receiving the transmitted signal, a method and a computer software product.

Abstract: Signals output from two filters included in a filter section 70 and differing in passband are respectively stored in different memories included in a memory section 80, and a positioning process is performed based on the signal stored in the memory. Specifically, the signal strength of a received signal is calculated by a coherent accumulation process and an incoherent accumulation process, and a signal system used for positioning is alternatively switched to a high-sensitivity system S1 or a high-accuracy system S2 as a result of determining whether or not the signal strength is equal to or greater than a threshold value.

Abstract: The present invention conducts the initial synchronization acquisition of the rapid and high precision ultra-wideband signal without complicatedness of hardware and increase in power consumption. For this purpose, a communication apparatus for exchanging information with an intermittent pulse train signal searches all phases among the pulses in the predetermined search resolution in the process to acquire initial synchronization of the input pulse, estimates the region where the peak phase of the largest output value exists, narrows the region where the peak phase exists up to the predetermined range by repeating the search for all phases in the estimated region in the next step, and conducts acquisition of detailed synchronization in the estimated region. In every step, the threshold value for judging existence of signal or a gain in the analog circuit is controlled for each step.

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: Disclosed is an apparatus for generating a ranging pseudo noise (PN) code used in a base station of a portable internet system of an orthogonal frequency division multiplexing access scheme, wherein a ranging pseudo noise mask value is generated using a cell ID number, and then the generated ranging pseudo noise mask value is stored in a memory. A final ranging PN code is generated using the stored ranging PN mask value and a status of a pseudo random binary sequence for generating a ranging PN code. With such a structure, the maximal 256-numbered ranging PN code values can be obtained simultaneously with each 144 bit-length.

Abstract: A DMB (digital multimedia broadcasting) receiver is provided, including: an equalizing unit compensating for distortion in CDM (code division multiplexing) channel signals in DMB based on a tap factor; and a channel estimation unit comparing version information contained in individual CDM channel control data in a pilot channel signal in DMB with version information contained in individual CDM channel control data in a previous pilot channel signal, and, if the version information match each other, using the CDM channel control data as a channel estimation sequence to perform a channel estimation process in a segment having no pilot symbol, and updating the tap factor of the equalizing unit according to a result of the channel estimation.

Abstract: In a signal processing apparatus a synchronizer acquires synchronization with the spreading code of an intermediate frequency signal converted from a signal received from a satellite in a global positioning system. A demodulator then demodulates a message contained in the intermediate frequency signal. A measuring unit outputs a primary signal to a predetermined signal line, the primary signal expressing positioning results for the apparatus as measured on the basis of the demodulated message. A secondary signal output unit attaches a predetermined header to a secondary signal and outputs the result to the predetermined signal line, the secondary signal containing at least the intermediate frequency signal, or a signal generated from the intermediate frequency signal.

Abstract: A frame timing synchronization technique for orthogonal frequency division multiplexing (OFDM) systems is presented. First, a coarse synchronization technique generates a coarse frame timing estimate. The coarse synchronization technique applies a sliding window differentiator to the output of a conventional auto-correlator to mitigate the plateau effect associated with conventional auto-correlation techniques. Second, a fine synchronization technique generates a fine frame timing estimate. The fine synchronization technique uses the coarse frame timing estimate to reduce the number of cross-correlation calculations. Additionally, the fine synchronization technique acquires a fine frame timing estimate based on a signal-to-interference ratio (SIR) metric, which is more robust to multi-paths and pseudo multi-paths caused by cyclic delay diversity (CDD) schemes than conventional cross-correlation synchronization techniques.

Abstract: In one embodiment, a timing-offset estimator calculates a correlation value for each sample of an OFDM signal having a cyclic prefix for each OFDM symbol. The correlation value is provided to a tapped delay line that applies a separate weight to each of 2V correlation values, where V is the length of the cyclic prefix and the weights are based on a triangular weighting scheme that increases linearly from the first value, peaks at the Vth value, and decreases linearly to the 2Vth value. A stream of combined, squared correlation values is generated by combining and squaring the 2V weighted correlation values for each sample of the OFDM signal. For each cyclic prefix of the OFDM signal, a timing-offset estimate is determined based on a detected peak value in the stream of combined, squared correlation values. A timing-offset estimator with triangular weighting scheme may be implemented using recursive processing.

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: To provide a mobile terminal capable of shortening the time required for deciding whether a terminal is located within the range of an area frequency at the time of the terminal power switched on, and securely performing location registration to a cell producing a large electric field intensity by recognizing an area frequency in advance.

Abstract: A receiver is configured to receive signals corresponding to spread spectrum information symbol streams. The receiver includes a plurality of channel circuits for receiving signals. Each channel circuit is responsive to a received signal for recovering an associated information signal therefrom. The associated information signal is spread by a sequence associated with the respective channel circuit. Each channel circuit is controlled by a clock signal derived by at least a first channel circuit of the plurality of channel circuits. The at least first channel circuit is responsive to the received signal for generating the clock signal by digitally filtering the received signal using digital filter coefficients adapted to the sequence associated with the at least first channel circuit.

Abstract: A simple and robust CTL is used for time tracking of multipath components of a spread spectrum signal transmitted over a wireless multipath fading channel. A digital code-tracking loop includes the implementations of despreading early and late data samples by use of a pseudonoise sequence, an error signal output generated by the despreading, and adjustment for a plurality of on-time, early and late samples, a data rate of a control signal provided as a fractional proportion of a data rate of error signals.

Abstract: A wireless communication device for receiving a frame (200) corresponding to a transmission time interval, the frame having a control channel (210) including at least two control channel elements (212, 214) and an embedded bit sequence, the location of which indicates a portion of the control channel used for radio resource assignment, wherein the portion of the control channel used for radio resource assignment may be less than the entire control channel of the frame having the embedded bit sequence, and wherein the at least two frames may use different portions of the control channel for radio resource assignment.

Abstract: A receiver includes a baseband processor for selecting a set of demodulation processing delays for received signal demodulation from a larger set of candidate delays. In one embodiment, the baseband processor selects the set of demodulation processing delays by calculating at least one metric for each demodulation processing delay in the set of candidate delays, iteratively reducing the set of candidate delays by eliminating one or more demodulation processing delays from the set as a function of comparing the metrics, and setting the processing delays for received signal demodulation to the candidate delays remaining after reduction. In a Generalized RAKE (G-RAKE) embodiment, the metric corresponds to combining weight magnitudes associated with G-RAKE finger delays. In a chip equalizer embodiment, the metric corresponds to coefficient magnitudes associated with equalization filter tap delays.

Abstract: A synchronization timing detecting apparatus includes a correlation calculator configured to generate a first correlation value by calculating a cross-correlation between an input signal being sampled and a reference signal or an auto-correlation of the sampled input signal, an interpolation processor configured to generate a second correlation value interpolating a plurality of the first correlation values having a different combination of sampling points of the input signal, and a detector to detect a synchronization timing based on the first and the second correlation values.

Abstract: Method and apparatus for performing midamble cancellation to remove midamble interference from the convolution tail of data field 1 and the first W?1 chips of the midamble field which results from the delay spread of the multipath channel and for canceling the first W?1 chip midamble spread in the data field 2, which operations are performed substantially simultaneously. The received burst, typically a TDD burst, is stored, the midamble interference and the corresponding parts in the received burst is removed and the resulting burst is applied to a multi-user detector to obtain the symbol sequences.

Abstract: Channel and correlation characteristics are determined for a composite signal. Respective combining weights for information from the composite signal are determined for respective ones of a plurality of candidate delays based on the determined channel and correlation characteristics. A group of delays, e.g., RAKE correlator delays or chip equalizer filter taps, is selected from the plurality of candidate delays based on the determined weights. Information from the composite signal for the selected delays is processed according to a spreading code to generate a symbol estimate. The invention may be embodied as methods, apparatus and computer program products.

Abstract: A synchronization acquiring device and method for realizing synchronization acquisition at high speed equivalent to that of parallel search with a simple constitution similar to that of series search. A synchronization acquiring device (100) has a superposition template acquiring section (120) for acquiring superposition template signals generated by superposing template signals on one another, a first correlation detecting section (110) for detecting preliminary correlation matching between a superposition template signal and the received signal and, if the preliminary correlation matching is not detected, detects preliminary correlation matching after replacing the superposition template signal with another superposition template signal, and a second correlation detecting section (130) detects, if preliminary correlation matching is detected, the final correlation matching between a superposition template signal out of the template signals and the received signal.

Abstract: Counter-clockwise and clockwise quadrant transitions are detected and accumulated with respect to a received complex signal over a certain time period. These transitions may then be compared in order to obtain information indicative of both a magnitude and phase of a carrier frequency error for the received signal. Additionally, zero-crossings of the received complex signal over the same certain time period are detected and accumulated. The accumulated crossings provide information indicative of frequency offset magnitude. The determined magnitude and phase of the frequency error may then be used to adjust a local oscillator frequency to provide for improved receiver performance.

Abstract: A CDMA radio system uses an adaptive filter in a receiver to mitigate multipath radio propagation and to filter out interfering signals. Characteristics of an initial stage of the filter preferably are determined by cross correlation of a generated pilot signal and the input signal with the integration of the correlation performed over a time period selected to be an integral number of symbol periods. The integration causes the portions of the cross correlation corresponding to the user subchannels to average substantially to zero, so that the pilot channel signal correlation is the primary contribution to the signal used to characterize the channel to establish the coefficients of the adaptive filter for the receiver.

Abstract: Provided are a method and apparatus for transmitting and receiving a signal at a variable data rate in human body communications. The apparatus includes a header generator, a data generator, a spreader, and a multiplexer. The header generator generates header information including a data rate. The data generator generates transmission data by repeating each data bit to be transmitted 0 to several times according to the data rate. The spreader spreads the transmission data using a spreading code in a desired frequency band. The multiplexer multiplexes the header information and the spread data.

Abstract: Method and apparatus for performing midamble cancellation to remove midamble interference from the convolution tail of data field 1 and the first W-1 chips of the midamble field which results from the delay spread of the multipath channel and for canceling the first W-1 chip midamble spread in the data field 2, which operations are performed substantially simultaneously. The received burst, typically a TDD burst, is stored, the midamble interference and the corresponding parts in the received burst is removed and the resulting burst is applied to a multi-user detector to obtain the symbol sequences.

Abstract: A method for obtaining a precise sampling frequency of a global positioning system (GPS) is applied in a GPS receiver. First, a radio frequency (RF) module of the GPS receiver is used to receive a satellite signal from at least one satellite. Then, a plurality of code delays of the satellite signal is calculated at a fixed time interval, and time differences between all adjacent two code delays among all the obtained code delays are calculated to obtain a plurality of time differences. Next, a mean value of all the obtained time differences is calculated. At last, a ratio between 1000 times of the mean value and the fixed time interval is calculated to obtain an error value, and the error is added to a standard sampling frequency of the RF module to obtain a new sampling frequency.

Abstract: A logic circuit comprises a logic module comprising a functional logic block supplying a functional result, and a functional flip-flop receiving the functional result and supplying a synchronous result. A module for checking the functional logic block comprises a checking logic block executing the same logic function as the functional logic block and supplying a checking result, checking synchronous flip-flops for applying data present at the input of the functional logic block to the input of the checking logic block, and means for comparing the functional result and the checking result and for supplying a first error signal.

Abstract: A receiver of a communication system includes means for receiving repetition-coded data. The receiver also includes means for generating symbol information from the received repetition-coded data. The receiver also includes means for storing symbol information over a predetermined period and means for making tentative symbol decisions by combining the stored symbol information.

Abstract: Embodiments of the present invention pertain generally to methods and systems of processing a global positioning satellite (GPS) signal. More particularly, embodiments of the present invention provide an improved discriminator function that utilizes the early, prompt, and late correlator values. For example, the improved discriminator function may be normalized based on all three of the early, prompt, and late correlator values. The improved discriminator function behaves linearly across a prescribed region whose width depends on the separation between correlators.

Abstract: Circuits, methods, apparatus, and systems for recovering a clock from a spread spectrum signal having a periodic modulation profile. The circuits generally include an error detector circuit configured to compare the spread spectrum signal and a recovered clock signal, and to produce a first error signal corresponding to the periodic modulation profile and a second error signal corresponding to phase differences other than the spread spectrum modulation, a record and playback unit configured to record a value to a frequency memory, said value based on the first error signal and produce a third error signal corresponding to a predicted periodic modulation based at least in part on the recorded value, and a signal generator configured to produce the recovered clock signal in response to the second and third error signals.

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: Provided is a synchronization error tracking device and method. The method and system estimates and corrects the synchronization error generated by time and frequency offsets during the data transmission interval and uses a module designed for initial synchronization or channel estimation without adding a new correlation operator. Further, a combining mark value and a synchronization position value acquired during the synchronization process are used.

Abstract: A system for operating a GPS receiver in a GPS-adverse environment includes a plurality of GPS receivers, a plurality of remote sensor interfaces (RSIs), and a computer management system. The GPS receivers are adapted to determine positional parameters based on the GPS satellite signals. A first set of GPS receivers is able to accurately determine its positional parameters and a second set of GPS receivers is unable to do so. Each RSI is associated with a respective GPS receiver. The RSIs are communication nodes in an ad hoc wireless network. The computer management system identifies a GPS receiver that is not accurately determining its positional parameters, and in response, causes GPS information to be provided from one of the first set of GPS receivers to the identified GPS receiver. The identified GPS receiver then determines its positional parameters accurately using the provided GPS information.

Abstract: A method of compensating for doppler phase errors includes receiving a signal at a receiver wherein the signal is spread using a pseudo-noise code, dividing the signal into a plurality of smaller coherent units and then compensating for induced doppler phase errors by analyzing the plurality of smaller coherent units. Analysis may include producing a plurality of coherent sums by summing across the smaller coherent units and then summing non-coherently the plurality of coherent sums. Analysis may also include demodulating a symbol from the smaller coherent units. A modulation technique may be selected from a plurality of modulation techniques and then be used to encode and transmit a symbol stream.

Abstract: An autocorrelation filter for use with a spread spectrum receiver. The autocorrelation filter can be used as a prefilter stage to reduce phase distortion present in a spread spectrum signal. The autocorrelation filter can be used to process the output from a lattice filter. The lattice filter is configured to remove magnitude distortion from the spread spectrum signal. The autocorrelation filter performs a series of correlations on the output of the lattice filter. The results of these correlations are integrated over a period of time to generate a running impulse response for characterizing and removing the phase distortion in the spread spectrum signal.

Abstract: Disclosed are a frame synchronization method and a receiver for a communication modem using the same. The frame synchronization method includes performing a correlation operation between a reception data stream and a preamble to output a synchronous signal; and computing correlation values between spreading codes and a reception data stream synchronized with the synchronous signal, wherein a maximum value of the computed correlation values is compared with a preset threshold value, and the outputting of the synchronous signal is performed again when the maximum value is smaller than the preset threshold value.

Abstract: A communication device performs a radio communication in an ultra wideband with the use of the impulse radio system. The communication device includes a receiver. The receiver is equipped with antennas, a correlation circuit, and a CPU. The antennas receive send signals from a transmitter. The correlation circuit detects a synchronization pulse having a longer cycle than a highly redundant data pulse among received signals. The CPU performs a synchronization process based on the synchronization pulse. The CPU establishes a channel based on the synchronization pulse, and selectively changes the antennas according to the received signal. In the case where the receive signal has not been received for a given period of time after the synchronization is established correlation signals is stopped outputting to start a polling signal. The correlation signals are output to obtain correlation of the receive signals.

Abstract: A system and a method to track GPS (Global Positioning System) satellite signal in a GPS receiver that includes an expanded capture window to rapidly reacquire the satellite signal after the satellite signal has been obstructed or when there is other type of signal loss. The expanded capture window includes a plurality of additional early and late correlations for maintaining synchronization of the GPS signal with a generated replica signal when positional error has accumulated during the time of the signal loss. The plurality of additional early and late correlations may be delayed from each other by a multiple of a fraction of a chip and may be performed in one or multiple channels of the GPS receiver. The adjoining code samples in the replica signal may also be offset by a fraction of a chip or by a multiple of the fraction of a chip.

Abstract: In a method for selecting a transmission target terminal in a zero-forcing beamforming algorithm, information about a channel capacity of each terminal is received from all K terminals. A terminal with a largest channel capacity is selected as an initial transmission target terminal. A determination is made as to whether the number of currently selected terminals, i, is equal to the predefined number N. If the number of currently selected terminals, i, is different from the predefined number N, information about channel capacities of remaining terminals except previously selected transmission target terminals is received until i is equal to N and a terminal with a largest channel capacity is selected as a transmission target terminal.

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: A method is provided for receiving a data frame in an ultrawide bandwidth network. In this method, a device receives an ultrawide bandwidth signal containing a data frame. The device then performs an acquisition operation during a first preamble in the data frame, and identifies a marker after the first preamble that indicates that the first preamble has ended. After this, the device performs a signal processing operation during a second preamble in the data frame. After the training, the device then receives a header in the data frame, and then receives a payload in the data frame. By having a marker between the two preambles, this method provides a receiving device with critical information regarding the timing of the preamble section of a frame.

Abstract: Satellite communication transmitter and receiver in a DVB-S2 system are provided. The satellite communication transmitter includes a modulator to modulate a satellite communication signal to be transmitted, and a spread spectrum unit to spread the modulated signal and transmit the spread signal. Accordingly, it is possible to reduce interference with a neighboring channel.

Abstract: A Method to maintain Synchronization Tracking in TDD Wireless Communication comprises the steps: divide a midamble into two parts, then detect the first part and the second part of the midamble; perform an auto-correlation property operation between the two parts and a part corresponding to a local midamble and obtain two peaks; compare the amplitude of the two peaks; advance or retard a local timer based on the result of the comparison. The interlaced sampling method will harm the SNR of channel estimation only very slightly. By using this method, the sample frequency can be decreased to only one time of the chip rate of a TD-SCDMA system while still maintaining the ability to track the downlink synchronization.

Abstract: A simple and robust CTL is used for time tracking of multipath components of a spread spectrum signal transmitted over a wireless multipath fading channel. A digital code-tracking loop includes the implementations of despreading early and late data samples by use of a pseudonoise sequence, an error signal output generated by the despreading, and adjustment for a plurality of on-time, early and late samples, a data rate of a control signal provided as a fractional proportion of a data rate of error signals.

Abstract: The object of the invention is to prevent reduction of the system capacity caused by the use of a channelization code belonging to the secondary scrambling code. Instead of trying to select a channelization code belonging to each of the primary and secondary scrambling codes for one cell in a conventional manner, selection of a channelization code belonging to the primary scrambling code is tried sequentially for a plurality of cells (S02, S04). If the selection of the code has been failed, it is determined whether selection is tried again under a different condition (S06). Then, when trying again, selection of a channelization code belonging to the secondary scrambling code is tried sequentially for the plurality of cells (S07, S09).

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 relates to a method of performing time drift compensation in a receiver (200) and a receiver (200) for performing time drift compensation. The basic idea of the invention is that a signal is received at the receiver. A control pulse is produced after a certain number of chips of the received signal has been received. A variable delay that is applied to the received signal is controlled by means of the control pulse. The resulting delayed signal is supplied to demodulation units (202, 203) in the receiver, in which delayed signal chips have been omitted or duplicated. A compensation signal is supplied to the demodulation units in the receiver, and this compensation signal indicates whether chips have been omitted or duplicated in the delayed signal. Finally, the delayed signal is demodulated such that the demodulation units consider the omission or duplication of chips in the delayed signal.

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.