Abstract: This invention generally relates to wired and wireless ultra wideband (UWB) data communications apparatus and methods, and in particular to UWB receiver systems and architectures. An ultra wideband (UWB) receiver system comprising: a receiver front end to receive a UWB signal; an analogue-to-digital converter coupled to said receiver front end to digitize said received UBW signal; and a correlator coupled to said analogue-to-digital converter to correlate said digitized UWB signal with a reference signal.

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: A method and apparatus for estimating and correcting baseband frequency error in a receiver. In one embodiment, an equalizer performs equalization on a sample data stream and generates filter tap values based on the equalization. An estimated frequency error signal is generated based on at least one of the filter tap values. A rotating phasor is generated based on the estimated frequency error signal. The rotating phasor signal is multiplied with the sample data stream to correct the frequency of the sample data stream. In another embodiment, a channel estimator performs channel estimation and generates Rake receiver finger weights based on at least one of the finger weights. An estimated frequency error signal is generated based on at least one of the finger weights.

Abstract: Described herein are ultra wideband (UWB) receiver systems, and applications thereof. Such a UWB receiver includes a receiver front end and a correlator coupled to the receiver front end. The receiver front end is configured to receive a UWB signal having a plurality of multipath components. The correlator is configured to correlate the UWB signal with a reference signal. The UWB signal includes a plurality of pulses, wherein each pulse has a plurality of multipath components. The reference signal also includes a plurality of multipath components of the pulse. The correlator includes at least one correlator module configured to correlate a plurality of the multipath components of the pulse with the reference signal.

Abstract: A GPS communication system including a server and a client, each including a GPS receiver, for reducing the code phase search space of the GPS receiver of the client. The communication system includes a transmitter for transmitting timing information from the server to the client to help the client locate a first satellite, and a receiver for using timing differences between the satellites to synchronize and locate other satellites. The code phase search space is reduced by reducing the number of phase hypotheses that must be calculated to establish communication between the server and the client.

Abstract: An uplink signal transmitted by a terminal is received by a satellite wireless communications system. The uplink signal includes a known information element, e.g., a reverse access channel (R-ACH) preamble, spread according to a spreading code specific to a component of a satellite wireless communications system, e.g., a pseudonoise (PN) sequence associated with a satellite beam. A correlation of the received uplink signal with the spreading code over a range of time shifts is determined. The known information element is detected from the determined correlation. The satellite wireless communications system is synchronized with the terminal responsive to detection of the known information element. For example, a delay may be assigned to a receiver of the satellite wireless communications system responsive to detection of the known information element.

Abstract: In the reception of a downlink MIMO CDMA signal, the receiving unit performs a simplified process of linear equalization that eliminates the need for inverting the correlation matrix. The correlation matrix is approximated to a good degree by a circulation matrix that is diagonalized by FFT operations, thus substituting two FFTs and one IFFT having a complexity of O ( L F ? ( N ? ? ? ) 3 + ( N ? ? ? ) 2 + 2 ? ( N ? ? ? ) 2 ? L F ? log 2 ? L F ) for the direct matrix inversion having a complexity of O(LF3).

Abstract: Radiolocalization receiver having a plurality of correlation taps, and including a module of cross-correlation detection in which spurious correlation terms are detected by statistical analysis of the frequencies of the candidate peaks. The system can restrict further integration to those taps whose frequency is outside the cross-interference signal, or trigger new acquisition of different space vehicles, upon detection of a cross-interference situation.

Abstract: Signal processing architectures for direct acquisition of spread spectrum signals using long codes. Techniques are described for achieving a high of parallelism, employing code matched filter banks and other hardware sharing. In one embodiment, upper and lower sidebands are treated as two independent signals with identical spreading codes. Cross-correlators, in preferred embodiments, are comprised of a one or more banks of CMFs for computing parallel short-time correlations (STCs) of received signal samples and replica code sequence samples, and a means for calculating the cross-correlation values utilizing discrete-time Fourier analysis of the computed STCs. One or more intermediate quantizers may optionally be disposed between the bank of code matched filters and the cross-correlation calculation means for reducing word-sizes of the STCs prior to Fourier analysis. The techniques described may be used with BOC modulated signals or with any signal having at least two distinct sidebands.

Abstract: A method and system for synchronization between a transmitter and a receiver in a communication system is provided. The receiver receives a plurality of signals from the transmitter. According to this method, a frequency burst is detected in the received signal at the receiver. The detected frequency burst is then validated on the basis of a synchronization burst in the received signal. Finally, the frequency and timing information present in the received signal is acquired for synchronization with the transmitter. The frequency and timing information is acquired on the basis of the validated frequency burst.

Abstract: Multiple Input Multiple Output (MIMO) system for receiving signals received from multiple inputs and transmitting signals to multiple output signal transmitters and multiple receivers for receiving transmitted signals. Processor for processing received location finder signals and for providing location finder processed baseband signals to a polar modulator for polar modulation of processed baseband signal. Processors for providing processed baseband signals to a non-quadrature or a quadrature modulator for modulation of processed baseband signal. Processor for processing and providing Orthogonal Frequency Division Multiplex Access (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA) signals for modulation and to multiple output transmitters.

Abstract: A matched filter decorrelator is described for efficiently performing a carrier frequency search while despreading a P/N long code constructed from two or more constituent codes such as codes A, B, C. The received signal is phase rotated into a frequency bin and partially despread, preferably over all but one of the constituent codes. To despread the final constituent code, the partially despread signal is input in parallel into frequency bins, where a phase rotator sets each input to a different bin. The frequency bins are then despread in parallel over the final constituent code, and an energy peak in one accumulator indicates which bin is the carrier frequency. Alternatively, a Fourier transform could be used over each of the frequency bins. By partially despreading prior to division into carrier frequency bins, hardware and computational burden are reduced as compared to prior art decorrelators. The present invention is particularly apt for use with an acquisition burst in a secure network.

Abstract: A wireless transmit receive unit (WTRU) and methods are used in a wireless communication system to process sampled received signals to establish and/or maintain wireless communications. A selectively controllable coherent accumulation unit produces power delay profiles (PDPs). A selectively controllable post processing unit passes threshold qualified magnitude approximation values and PDP positions to a device such as a rake receiver to determine receive signal paths.

Abstract: Method and apparatus to compute the combiner coefficients for wireless communication systems for a space-time solution. One embodiment trains the weights on a signal known a priori that is time multiplexed with other signals, such as a pilot signal in a High Data Rate, HDR, system, wherein the signal is transmitted at full power. A Minimizing Mean Square Error, MMSE, approach is applied allowing weight combining on a per path basis. The weights are calculated as a function of a noise correlation matrix and spatial signature per path. The noise correlation matrix is determined from an autocorrelation matrix of the received signal. In one embodiment, the MMSE approach is applied to a non-time gated pilot signal.

Abstract: A receiving system dynamically searches a communications band for transmissions of messages having the same nominal communications parameters, including the use of the same spreading code, but having potentially different specific frequencies and code-phases. The receiver samples the communications band at each code-phase of the spreading code over a span of down-converted transmission frequencies. When a message element is detected at a particular code-phase and frequency, it is forwarded to a demodulator that demodulates the message and sends it to its intended destination. This technique allows each transmitter to be independent of the receiver. In a preferred embodiment of this invention, a Fast M-Sequence Transform (a Walsh-Hadamard Transform) is used to determine the power level at multiple code-phases at a given frequency in parallel, thereby substantially reducing the time required to search for transmissions at each discrete code-phase.

Abstract: Techniques to detect radar signals in a communication signal for a wireless system are described.

Abstract: A spread-spectrum demodulator includes a spreading code generating section, correlation value computing section, data signal demodulating section, peak signal detecting section, and spreading code generation control section. The spreading code generating section generates a spreading code for correlating with a received spread signal. The correlation value computing section computes a correlation value between the spread signal and the spreading code output from the spreading code generating section. The data signal demodulating section detects the peak of an output from the correlation value computing section and demodulates a data signal on the basis of the detected peak. The peak signal detecting section detects the peak of the output from the correlation value computing section. The spreading code generation control section changes the shifting direction of the spreading code relative to the spread signal every time a peak is detected by the peak signal detecting section.

Abstract: here is provided a new multi-user receiver configuration technique which solves the problems of the user signal separation function of the multi-user receiver such as the interference canceller, decorrelator, and least square error detection. That is, there is provided a code-division multiplex signal decorrelation/identification method for realizing much more excellent performance than the aforementioned methods in the aspect of the power band amplitude product required for one-bit transfer as the evaluation reference of the CDMA method. A function for successively judging the best user is added to the conventional least square error detector MMSE-D shown by a dotted line in the block diagram of the successive detection type least square error detection method (SD-MMSE).

Abstract: A method and apparatus for channel estimation in a rake receiver of a CDMA communication system operates with a finite-impulse-response channel estimation filter with L taps and having a fixed delay. A pilot sequence of a received sequence of data from a channel of the communication system on the rake receiver is input. A quality of the channel of the communication system is determined using noise or Doppler measurements. These measurements are used in adjusting a bandwidth of the filter to accommodate the channel quality while keeping the fixed delay, which minimizes the delay buffer size. The filter is then used to operate on the received sequence of data to provide coherent modulation.

Abstract: A method of determining an acquisition indicator bit AIs at a receiver in a communication system which includes receiving multiplexed acquisition indicator bits y=B×AI+n, where B is the signature matrix known at both base station and UE, AI is all the acquisition indicator bits and n represents noise. Next, an estimated value of the acquisition indicator bit AÎMMSE (s) as a function of ? j ? ? B T ? ( s , j ) × y ? ( j ) is calculated, where BT(s,.) is the s-th row vector of the transposed matrix BT for acquisition indicator bit AIs. Finally, the acquisition indicator bit AIs is set as follows: AIs=?1, if AÎMMSE(s)<R AIs=0, if R?AÎMMSE(s)<U AIs=1, if AÎMMSE(s)?U, where R and U are decision thresholds.

Abstract: The present invention provides a new baseband integrated circuit (IC) architecture for direct sequence spread spectrum (DSSS) communication receivers. The baseband IC has a single set of baseband correlators serving all channels in succession. No complex parallel channel hardware is required. A single on-chip code Numerically Controlled Oscillator (NCO) drives a pseudorandom number (PN) sequence generator, generates all code sampling frequencies, and is capable of self-correct through feedback from an off-chip processor. A carrier NCO generates corrected local frequencies. These on-chip NCOs generate all the necessary clocks. This architecture advantageously reduces the total hardware necessary for the receiver and the baseband IC thus can be realized with a minimal number of gate count. The invention can accommodate any number of channels in a navigational system such as the Global Positioning System (GPS), GLONASS, WAAS, LAAS, etc.

Abstract: Some embodiments of the invention provide devices, systems and methods of wireless signal detection. For example, an apparatus in accordance with an embodiment of the invention includes a detector to determine whether an incoming input is a wireless communication signal intended for reception, based on an operation applied to a cross-correlation value and an auto-correlation value.

Abstract: A spread spectrum receiver whose de-spreading process based on transformed spreading codes is provided. Instead of de-spreading with original spreading codes, this approach de-spreads received signal with the spreading codes transformed from the original codes in order to eliminate the negative impact of system impairments such as frequency offset to a spread spectrum receiver. Before de-spreading with the transformed code, the received signal goes through the same transformation as the original codes do. After a transformation, the transformed codes may exist some undesirable property such as spreading code having DC content. An approach is given to cancel unwanted side effects relating the transformed spreading codes. The approaches are very effective for spread spectrum system based on frequency modulation scheme such as MSK.

Abstract: Systems and methods for a cumulant-based discriminator for global navigation satellite system code alignment are provided. In one embodiment, a method for determining a misalignment between a GNSS coarse acquisition code signal and a replica code is provided. The method comprises producing code samples of a spread spectrum signal received from a satellite; multiplying the code samples by a current value of a replica code; and calculating a set of multiple-order cumulants based on the code samples multiplied by the current value of the replica code.

Abstract: The invention related to a modulator for a communications system. The modulator comprises a spread spectrum coder, a pulse code modulator having a signal input port connectable to a signal output port of the spread spectrum coder. The modulator performs a robust and error free modulation and coding scheme by using a modified spread spectrum scheme combined with pulse code modulation. The communication system contains a low data rate, noise robust modulation and coding scheme using a very simple transmitter. This results in a very straightforward transmitter circuit, reducing size and costs of the transmitter.

Abstract: A system and method are provided that can detect any part of a multipath impulse radio signal. More specifically, the method compares a template pulse train and the multipath impulse radio signal to obtain a comparison result. The system performs a threshold check on the comparison result. If the comparison result passes the threshold check, the system locks onto any part of the multipath impulse radio signal including a direct path part and at least one multipath reflection part. The system may also perform a quick check, a synchronization check, and/or a command check of the multipath impulse radio signal.

Abstract: A filter (201) accepts spreading code sequences or the like as input sequences of a chip rate 1/D, the accepted spreading code sequences are sequentially delayed and distributed by delay circuits (202) connected in series, delay times of individual signals are an arithmetical progression with a chip length D being a common difference D, the individual signals are amplified with spreading codes by amplifiers (203), amplification factors for the individual signals are a geometrical progression of a common ratio r, the sum of the amplified signals is obtained by addition in an adder (204), and the result is sequentially output as an output sequence.

Abstract: Channel impulse response estimation employs a training sequence to enable correction for multipath and other disturbances affecting a signal during transmission via a digital wireless communication channel. High-speed packet transmission rates, with a training sequence for each packet, are made possible by training sequence construction enabling fast algorithm processing of received signals for impulse response estimation. Upon reception, a Toeplitz-type mathematical representation is constructed based on transmitted and received versions of a training sequence. The Toeplitz-type representation may then be processed by application of fast algorithms, such as Levinson-type algorithms, to determine coefficients representative of the communication channel impulse response. These coefficients, applied to an adaptive equalizer type of filter, enable correction for signal disturbances incurred in transmission. Channel impulse response estimation methods and systems are described.

Abstract: A semiconductor integrated circuit for processing a plurality of received broadcast signals, such as GPS signals, is operable in two modes: acquisition and tracking. In an acquisition mode, sample reducer combines samples of a received signal for correlation with a locally generated version of a GPS code. In a tracking mode, the sampled signal is provided direct to the correlators without sample reduction. The same correlators are thereby used to increase acquisition speed.

Abstract: A terrestrial C/A code GPS receiver system digitally samples, filters and stores a segment of 11 half chips of the received composite as a binary number and multiplexes this number for parallel correlation with each of a series of multibit code replicas for the satellites to be tracked. Each of the time delay specific correlation products are accumulated in a cell of a memory matrix so that at least twenty two delays for each satellite may be evaluated each code period providing fast reacquisition, even within a city intersection, as well as correction of multipath tracking and multipath interference. All cells of the memory matrix may be used for an acquisition of a single satellite in about 4 ms. Two satellite tracking, in addition to altitude hold, uses cross track hold alternating with clock hold to update the cross track estimate. Single satellite tracking uses cross track and clock hold together. Navigation data is updated with detected changes in motion including turns.

Abstract: A semiconductor integrated circuit for processing a plurality of received broadcast signals, such as GPS signals, is operable in two modes: acquisition and tracking. In an acquisition mode, a memory arrangement comprising two circulating shift registers circulates samples of a received signal for correlation with a locally generated version of a GPS code. In a tracking mode, the sampled signal is provided direct to the correlators. The same correlators are thereby used to increase acquisition speed.

Abstract: A RAKE receiver circuit generates combining weights based on channel estimates and combining statistics that comprise channel coefficient statistics, noise statistics, and channel estimation error statistics. Together, these statistics incorporate the relationships in noise and channel estimation across two or more RAKE fingers, and thus improve combining weight generation. Exemplary determination of statistics comprises channel coefficient cross-correlations, noise cross-correlations, and channel estimation error cross-correlations. Determination of the statistics can be varied based on, for example, the assumption of default or nominal signal models.

Abstract: A system and method are provided for canceling interference present in a local channel signal received at a receiver. The system includes a controller and a finger demodulator assembly. The controller is capable of selecting at least one interfering pilot channel signal that has a signal strength above a threshold, where the selected interfering pilot channel signals comprises an interfering set of pilot channel signals. The finger demodulator assembly can then be capable of producing a corrected local channel signal based upon the interfering set of pilot channel signals during the idle state and/or access state.

Abstract: The ultra wide band communication system of the present invention includes a transmitter (station) and a receiver (station). The transmitter and the receiver employ spreading code comprised of code groups, which respectively comprise varied, auto-correlated codes. Consecutive information bits are spread and de-spread with differing code and the code groups are correlated with each other (e.g., orthogonal) so as to reduce channel impulse response estimation noise. At the receiver, subsequent channel estimates can be added or averaged with an initial channel estimate so as to reduce the channel impulse response estimation noise and thereby provide a relatively more accurate channel response.

Abstract: At noise component addition section 105, a noise equivalent value equivalent in size to noise component is calculated using a constant which is dependent on a difference of spreading factors between a common pilot channel and packet channels, and at correlation matrix and correlation vector calculation section 106, the noise equivalent value is added to diagonal elements of an autocorrelation matrix. At weight calculation section 107, an optimal weight is calculated using the autocorrelation matrix whose diagonal elements have been added the noise equivalent value, and at adaptive equalization section 108, equalization of reception signal is carried out. Thereby, noise enhancement produced in the packet channels after the equalization due to the difference between the spreading factor of the common pilot channel and the spreading factor of the packet channels can be reduced.

Abstract: System and method for improving the detection performance of a wirelessly transmitted signal. A preferred embodiment comprises specifying a desired response for missed channel detection and false alarm probabilities for a plurality of signal qualities and determining if a channel detection threshold is based on missed channel detection or false alarm probabilities for the plurality of signal qualities. A signal quality estimate of a channel can be inferred from a signal quality measurement of a second channel, wherein the channel and the second channel are sourced by a single transmitter. The channel detection threshold can be adjusted based upon the previously determined required response and the signal quality estimate of the channel.

Abstract: Provided is a method of compensating for energy loss and eliminating inter-symbol interference (ISI) and inter-chip interference (ISI) in wireless signals, and a rake receiver for wireless LANs adopting the same. The rake receiver compensates for energy loss of a CCK signal transmitted in a multi-path wireless channel environment and eliminates ISI and ICI from the received CCK signal because a DFE structure per chip used for calculating ICI components, is connected in parallel with a DFE structure per symbol, thus eliminating ISI and ICI components.

Abstract: A method for initial synchronization in a mobile telecommunications network to connect a mobile terminal (10) to a base station (12). The mobile terminal has a search frequency list comprising a limited number of search frequencies. The method comprises the step of searching for an available frequency in the order of the search frequency list. The search frequency list further comprises count values, indicating how frequently the corresponding frequency has been used, wherein the order of at least some of the search frequencies depends on the count values.

Abstract: System and method for combining maximizing a received signal in a multipath environment. A preferred embodiment comprises a rake receiver (for example, rake receiver 1100), created from switched capacitors, with N fingers. Each of the fingers is coupled to a signal input for a period of time to accumulate a charge on a storing capacitor (for example, storing capacitor 1115). The charges stored on the storing capacitors can then be read-out to produce a value. The rake receiver can implement either equal ratio combining or maximum gain combining to further improve received signal strength.

Abstract: A signal-path delay-estimation method includes correlating a computed coarse delay profile of at least one detected signal path cluster with a waveform to yield a strongest correlated peak for each of the at least one detected signal path cluster. The method also includes, for each of the at least one detected signal path cluster, using the strongest correlated peak to determine an adjusted delay-profile phase, re-sampling the computed coarse delay profile in accordance with the adjusted delay-profile phase, and detecting signal-path-cluster edges using the re-sampled computed coarse delay profile. This Abstract is provided to comply with rules requiring an Abstract that allows a searcher or other reader to quickly acertain subject matter of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: Step 2 demodulation is conventionally performed using a secondary synchronization channel that correlates a received signal at a known time slot location against each of a plurality of sequences associated with the secondary synchronization code. The disclosed implementation proposes the use of a different synchronization channel to complete the step 2 process. More specifically, a complete synchronization channel correlator is used for the demodulation where the received signal at the known time slot location is correlated against a combination of the primary synchronization code and each of the plurality of secondary synchronization codes. This combined correlation produces enhanced step 2 performance in terms of acquisition time or signal-to-noise ratio.

Abstract: A communications apparatus and method use tapped delay lines as multiplexers and demultiplexers. In one embodiment, a receiver (100) uses a tapped delay line (110) as a demultiplexer to acquire a burst communication at very high data rates in the range of 2.5 to 80 Gbps with low preamble overhead. A sliding window correlator (114) continually samples the delay line (110) to determine when a PN encoded word is contained therein. The transmission frequency is pre-acquired before any data is present through the use of a ring oscillator frequency calibration loop (130) that is imbedded within the tapped delay line (110).

Abstract: In a spread spectrum system, methods and despreader architectures for despreading the received spreaded codes with the use of a single correlator and a single correlation code is provided. Before despreading the incoming received spreaded codes, a single correlation code is generated using a symbol from a set of symbols that has been mapped into a set of differential encoded PN codes. Despreading output samples for each received spreaded code are obtained by correlating the received spreaded code with this single correlation code. Correlation is accomplished by multiplying each received sample of the received spreaded codes with the correlation code samples and accumulating the products of this multiplication. After correlation, the index for the maximum or minimum peak of the despreading output samples for each code is identified. This index can then be mapped into a symbol corresponding to the transmitted information.

Abstract: A spread spectrum base station for receiving a plurality of spread spectrum signals and a plurality of phased spread spectrum signals includes an antenna and a plurality of delay devices connected to the antenna, each delay device outputting a time-delayed spread spectrum signal. A combiner is connected to the plurality of delay devices for combining the time-delayed signals and the phased signals, the combiner outputting a combined signal. An RF/IF section is connected to the combiner and converts the combined signal into in-phase (I) components and quadrature-phase (Q) components. A plurality of despreaders are connected to the RF/IF section, each despreader despreading the I and Q components of the combined signal into a despread signal. A controller is connected to each of the despreaders and controls a corresponding delay device.

Abstract: A demodulator such as a Fast Hadamard Transform (FHT) based demodulator is used to demodulate all channels in a code space with code length equal to the data channel code. Since the codes for overhead control channels are usually longer, the control channel data is only partially uncovered. Once the necessary further processing is performed and the information to fully uncover the control channels is available, the control channel data is fully demodulated. By only processing one partially uncovered secondary control channel, the present invention reduces the implementation complexity. A hardware implementation of the above method, requires fewer data processing operations, and reduces data processing delays, resulting in lower power consumption.

Abstract: A method for supporting a determination of the correlation between at least one received code modulated signal and at least one available replica code is shown. In order to reduce the total memory size required for such correlations, the method comprises storing signal samples of the at least one received code modulated signal with a first rate in a memory. The stored signal samples are then read with a second rate from the memory for determining a correlation between the read signal samples and samples of the at least one available replica code, wherein the second rate is higher than said first rate. The disclosure relates equally to a corresponding electronic device, to a chip for such an electronic device, to a system comprising such an electronic device and to a corresponding software product.

Abstract: A method is provided for performing a clear channel assessment in a local device. The local device receives signal energy in a wireless channel and splits the received signal energy into a real portion and an imaginary portion. It determines a real portion of a squared signal energy by subtracting a squared imaginary portion of the signal energy from a squared real portion of the signal energy, and determines an imaginary portion of the squared signal energy by calculating twice the product of the real and imaginary portions of the signal energy. It can perform a signal detection function on the real and imaginary portions of the squared signal energy to produce a clear channel assessment signal that indicates whether a set signal type is present in the wireless channel. This clear channel assessment signal can be used to determine whether the local device should remain in a low-power mode.

Abstract: A digital broadcast receiving apparatus for receiving a broadcast signal generated by combining sub signals modulated using a random sequence generated based on an initial value set in accordance with a frequency of a broadcast channel by a signal transmission control use signal and a main signal generated based on information source data and reproducing the information source data contained in the received broadcast signal.

Abstract: A method and arrangement for use in a single user detector in a CDMA multi-path system, comprising providing a finite impulse response (FIR) filter; and configuring the FIR filter to derive at least a first, then a second, then a third, then a fourth of the following parameters for single user detection: R (auto-correlation) function; L (Cholesky decomposition) value; X value representative of the complex conjugate of a channel impulse response multiplied and summed with time shifted versions of a received signal; back substitution value Y (function of R, X and L); and back substitution value S (function of R, X, Y and L).

Abstract: A spread spectrum radio transceiver includes a high data rate baseband processor and a radio circuit connected thereto. The baseband processor preferably includes a modulator for spread spectrum phase shift keying (PSK) modulating information for transmission via the radio circuit. The modulator may include at least one modified Walsh code function encoder for encoding information according to a modified Walsh code for substantially reducing an average DC signal component to thereby enhance overall system performance when AC-coupling the received signal through at least one analog-to-digital converter to the demodulator. The demodulator is for spread spectrum PSK demodulating information received from the radio circuit. The modulator and demodulator are each preferably operable in one of a bi-phase PSK (BPSK) mode at a first data rate and a quadrature PSK (QPSK) mode at a second data rate. These formats may also be switched on-the-fly in the demodulator. Method aspects are also disclosed.