Abstract: The invention aims at adaptive array diversity reception of high convergence speed of combined weight by a simple signal processing, in a receiver by time division transmission system. Signals received by antennas (branches) are converted into base band signals in a receiving circuit, and are combined by a complex multiplying section and complex adder. The weight of the complex multiplying section is calculated by a weight calculating section. In the weight update algorithm of the weight calculating section, the step size in the least mean square is variable. That is, the initial value is set at a large value, and is decreased according to the lapse of time in each time slot, and is initialized at every change of time slot. As a result, by the same amount of calculation as in ordinary least mean square, the convergence speed of weight updating can be enhanced.

Abstract: A CDMA cellular system does not require accurate synchronization between all base stations and is capable of distinguishing the base stations from each other without the need for a complex process. When two element codes are multiplied with shifted timing to generate a spreading code, different codes that do not agree with each other when cyclically shifted are generated for the respective base stations. Spreading codes of the base stations are distinguished even when the base stations are not kept in synchronism with each other. In the CDMA cellular system which uses such spreading codes, when frame synchronization is achieved using a perch channel spread by a spreading code that is common to all the base stations, a signal transmitted from one of the base stations is de-spread on the basis of a first element code which is of the same timing (phase) with respect to a frame in all the base stations.

Abstract: A system (101-139) receives a transmitted optical signal and generates an orthogonal despreading code that is different than the code used to spread the transmitted signal. The system (101-139) then despreads the received signal using the despreading code. By using a code to despread the received signal that is different than the code used to spread the signal, the overall interference in the system can be reduced and even eliminated.

Abstract: A method includes receiving a transmitted signal and generating an orthogonal despreading code that is different than the code used to spread the transmitted signal. The method then despreads the received signal using the orthogonal despreading code. By using a code to despread the received signal that is different than the code used to spread the signal, the overall interference in the system (100) can be reduced.

Abstract: A system and method for canceling interference present in a code-division multiple access (CDMA) channel signal received at a CDMA receiver that is caused by multipath components of a transmitted pilot channel signal or by soft handoff conditions is computationally efficient because it operates at symbol rates. The channel signal from which such multipath interference is canceled can be either a traffic (data) channel or the pilot channel itself. Interference signals are produced in groups corresponding to the fingers of the CDMA rake receiver. The interference signals corresponding to each finger are used to cancel interference in the other fingers.

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, of the following parameters for single user detection: R (auto-correlation) function; L (Cholesky decomposition) value; X value; Y value; and S value.

Abstract: A receiving apparatus Doppler spread estimator includes a receiver receiving signals over a transmission channel that varies over time due to fading and converting the signals to digital samples for processing. A stationarizer operatively associated with the receiver stationarizes the digital samples. An estimator is operatively associated with the stationarizer for estimating spectral density of the stationarized digital samples. The correlator is operatively coupled to the estimator for correlating the spectral density estimates with functions corresponding to hypotheses of plural Doppler spread values to select one of the Doppler spread values as an estimate of actual Doppler spread.

Abstract: A pseudo noise code acquisition apparatus in a direct sequence spread spectrum receiver capable of minimizing a retard involved in the updating of a pseudo noise code sequence, thereby achieving a reduction in pseudo noise code acquisition time. The apparatus is configured to conduct a pseudo noise code update prior to a threshold comparison after a spread spectrum signal is subjected to despreading and correlation for a desired number of chips. By this configuration, when it is determined, based on the result of the threshold comparison, that acquisition of a desired pseudo noise code has failed, it is possible to receive data associated with a new pseudo noise sequence without any delay.

Abstract: Downlink diversity in a CDMA system is provided by employing Walsh codes in conjunction with M transmit antennas at a common base station serving K mobiles, where M may or may not be to equal to K. The present invention provides methods and apparatus for improving downlink diversity in a CDMA system. Each transmit antenna transmits a signal representing the result of the modulation of Walsh codes by data signals for each of the K mobiles, assuming there is data pertaining to a particular mobile. The assignment of Walsh codes is accomplished in accordance with a transmission matrix T. The transmission matrix maps the user data symbols onto the Walsh codes for each antenna and is preferably designed such that its columns are representative of the transmit antennas and orthogonal.

Abstract: A CDMA receiver with a reduced number of high speed adders is provided, wherein integration for one symbol period is performed for each value of spreading code corresponding to a particular user signal by the use of a high speed adder, first and second switches, and a register group. The integrated values are stored in respective first registers of the register group and then despread in accordance with respective spreading codes. As a result, an adder with a slow operational speed can be employed as a first slow speed adder that adds the values from first multipliers, and a second slow speed adder for addition of the values of the first registers. Therefore, a common pilot signal and a user signal can be despread with only one high speed adder.

Abstract: Tone sequences in a frequency hopping arrangement are generated and assigned by advantageously employing a combination of a sequence generator and a sequence assignor to generate sequences and assign them on a time slot by time slot basis. In a transmitter, the sequence generator and sequence assignor, in combination with a user tone assignor are employed to generate and assign tone sequences to a user on a time slot by time slot basis. In a receiver, the sequence generator and sequence assignor, in combination with a user tone identifier are employed to generate sequences and to identify incoming tone sequences to a user on a time slot by time slot basis. Specifically, the sequence assignment in a time slot is such that a prescribed plurality of sequences is assigned to a particular user.

Abstract: A Code Division Multiple Access system and method of operation provides reduced interference for received signals and improved signal acquisition and processing with reduced computational complexity. The system includes a base station coupled to an antenna array of at least two or more antennas and serving a plurality of users. A receiver in the base station includes a universal inverse cross-correlation matrix coupled to the antenna array, a signal acquisition and a signal processing circuit serving each user. Each signal acquisition circuit comprises a series of delay stages in which the incoming antenna signals in each stage are correlated with a spreading code and combined in a multiplier coupled to the universal inverse cross-correlation matrix which facilitates improved time delay estimation for signal acquisition.

Abstract: In response to an error signal, a pseudo-noise generator (312 or 416) generates an on-time pseudo-noise signal, an early pseudo-noise signal delayed by less than one-half of a chip interval, and a late pseudo-noise signal advanced by less than one-half of a chip interval. A correlator (302 and 304, or 404) correlates a received signal with the early and late pseudo-noise signals to generate the error signal. The combination of the pseudo-noise generator (312 or 416) and the correlator (302 and 304, or 404) creates a loop in which the on-time pseudo-noise signal tracks a received pseudo-noise code more closely than in prior art devices and enables a deinterleave and decode device (210) within the receiver to demodulate the received signal more effectively.

Abstract: For one embodiment, a Random Access Channel (RACH) preamble modulation method and apparatus are disclosed in which the real and imaginary components of a complex RACH preamble are filtered in corresponding pulse shaping filters. Consequently, the phase transitions in the resulting signal are limited at all chip positions, and the resulting quadriphase codes produce transmitted signals with lower Peak-to-Average Power Ratios (PAPRs) than those that result using conventional Hybrid Phase-Shift Keying (HPSK) modulation schemes. On the other side, the resulting quadriphase synchronization code retains the same aperiodic autocorrelation magnitude as the original binary code, optimized to produce the minimum probability of incorrect synchronization.

Abstract: A communication apparatus for communicating with one base station among a plurality of base stations is provided with a present position detecting device for detecting a present position of the communication apparatus and outputting present position information indicative of the detected present position. The communication apparatus is also provided with an identification information obtaining device for obtaining identification information of respective one of the base stations on the basis of the present position information outputted by the present position detecting device. The communication apparatus is further provided with a specifying device for specifying said one base station on the basis of the identification information obtained by the identification information obtaining device.

Abstract: A method and apparatus to perform a signaling protocol between a base station and a remote handset of a digital cordless telephone to simplify the digital cordless telephone. A pseudo-noise (PN) code correlation detector of a direct sequence spread spectrum (DS/SS) module, included in a base station and a remote handset, detects an inverted correlation state in a received digital signal when an strong inverted direct current (DC) content is sensed in the received digital signal. This is indicative that an inverted code sequence was sent in the received digital signal. By pulse-keying the inverted correlation state, commands may be encoded to implement a simplified cordless signaling protocol. For the base station, the two commands encoded are a ‘Flash’ and a ‘On-hook/Off-hook’ toggle. For the remote handset, the two command encoded are a ‘Ring’ and a ‘Page/Find’.

Abstract: A synchronization acquiring method capable of reducing the length of time required to perform in wireless communication a synchronization acquiring operation is provided when the mobile station transits from a sleep state to an active state. A synchronization acquiring apparatus capable of performing such a synchronization acquiring method is also provided. The method has the following three steps. In the first step, multiple correlation values are obtained between the input data supplied from a base station to the mobile station and multiple phases of a spreading code multiplied to the input data in the mobile station before the mobile station transits from the active state to the sleep state, multiple phases of the spreading code that correspond to the correlation values are determined, and the multiple phases are stored. In the second step, phases of the spreading code multiplied to the input data are determined using the phase when the mobile station transits from the sleep state to the active state.

Abstract: Techniques for searching in asynchronous systems are disclosed. In one aspect, a plurality of codes, such as SSCs, are correlated with a received signal at a plurality of offsets to produce a code/slot energy corresponding to each code/slot boundary pair. Unique subsets of the code/slot energies are summed to produce code sequence energies, the maximum of which indicates a located code sequence and slot boundary. In another aspect, the correlation is performed by sub-correlating the received signal with a common sequence, and performing a Fast Hadamard Transform (FHT) on the results. In yet another aspect, one sub-correlator can be used to search a plurality of peaks simultaneously. Various other aspects of the invention are also presented.

Abstract: Method for transmitting an information representative of the number of spreading codes allocated to the mobile stations in communication with a base station of a mobile telecommunication system,

Abstract: A spread spectrum communication system for wirelessly transporting autonomously time-referenced telecommunication data couples the data streams to mutually synchronized multiplexers, outputs of which are encoded and applied to associated I and Q channel spreaders, which spread the respective multiplexed data streams using mutually orthogonal spreading code sequences. The resulting spread I-channel data streams are coupled to I and Q channel summing units outputs of which are applied to respective channels of a QPSK modulator and transmitted to a receiver site. At the receiver the QPSK signals are correlated in despreading correlators and then decoded and demultiplexed to produce data streams, corresponding to those applied to the transmitter.

Abstract: A bidirectional direct sequence spread spectrum half-duplex RF modem which can be applied to transmit and receive numerous types of analog and digital pulse modulation. The modem incorporates two different SAW devices fabricated on a single monolithic substrate. A first SAW device is used as a resonator in the oscillator circuit while a second SAW device is used as the correlator for transmit and receive operations. The RF modem operates as an analog or digital pulse transmitter and receiver and is adapted to be generic and versatile enough to be used in many different types of data communication systems, such as OOK, PWM and PPM. The RF modem can be used as the physical (PHY) layer in a layered communication system such as the ISO OSI communication stack. In an alternative embodiment, the transmission bit rate is increased using a plurality of correlators wherein each is configured with a unique function (i.e., code) that is orthogonal with all other functions.

Abstract: For determining characteristics of components of a communication channel, for example of a transponder in a communication satellite, a clean carrier signal f(t) is modulated with a pseudo noise signal PN(t) and transmitted through the communication channel at a level below the level of a payload signal which is transmitted via the communication channel simultaneously. The received signal s′(t) is correlated with same pseudo noise signal PN(t) to obtain a recovered carrier signal f′(t). Both the clean carrier signal f(t) and the recovered carrier signal f′(t) can be used to determine the desired characteristics. Since the PN modulated clean carrier signal s(t) is transmitted at a low level, it is possible to perform measurements without switching off the payload signal.

Abstract: Methods and architectures for data message bit synchronization of a spread spectrum signal having a repeating sequence of pseudorandom code bits modulated with data message bits having a data bit time that is an integer number of a repeat time of the pseudorandom code bits. In one embodiment, an adjusted bit sync offset time is determined for each of a plurality of signals for which bit sync offset time is not known based on a corresponding clock error corrected propagation time for each signal, based on a known bit synch offset time and based on a clock error corrected propagation time of the signal for which bit synch offset time is known.

Abstract: A method and system are disclosed for facilitating the timing (e.g., the known relative timing differences) of base stations (BSs) in asynchronous CDMA mobile communications systems. A plurality of mobile stations (MSs) measure the relative time differences between various pairs of BSs, and these measurements are stored by the BSs. A source BS sends to an MS, in a neighbor list message, estimates of the relative time difference between the source BS and each of the BSs on the neighboring cell list. Each BS on the list can maintain a relative time difference estimate table, which can be updated continuously from the reports received from MSs. Subsequently, the BSs can send entries from this table to the MS in the neighbor list message. Using this novel technique, the BSs have known relative timing differences. Consequently, when the MS initiates a cell-search for a candidate BS, the MS already has an estimate of the timing of that BS as compared to its source BS.

Abstract: Methods and apparatus for synchronization of a transmitter and a receiver are based on orthogonal sequences having optimized correlation properties. The transmitter may generate signed versions of S-Hadamard sequences that are obtained by position-wise scrambling a set of Walsh-Hadamard sequences with a special sequence having complex elements of constant magnitude. The receiver estimates a time location and sequence identity of a received version of the synchronization signal.

Abstract: A radio communications system in which a desired signal can be accurately discriminated from interfering signals, even when signals from a plurality of transmitters are received simultaneously, is provided. A transmitter for this system communicates information using signals which are repeated over predetermined periods. A pulse generator generates pulses having a predetermined repetition period based on an information bit to be communicated. Transmission means transmit the pulses generated by the pulse generator. Pulse amplitude alterating means control the amplitude of the pulses to be transmitted by the transmitting means in accordance with a predefined pattern under the control of a control unit.

Abstract: A spread spectrum receiver processes signals from a plurality of sources modulated by different spread spectrum codes by sampling the signals as received to produce an integer series of sampling segments at a sampling rate at least twice a chip rate of the codes, each sampling segment containing an integer number of bits representing a fraction of a chip of the codes, time division multiplexing each sample segment into a number of channels, correlating the bits in each sample segment in each channel in parallel with a source specific series of locally generated sequential code samples differing by one bit, summing each parallel correlation, and accumulating the summed parallel correlations for each code sample in each channel at at least the chip rate to derive data related to each of the sources.

Abstract: A method to expediently perform search/correlation operation between an internal pilot pseudonoise (PN) sequence and an incoming pilot PN sequence. This operation is used to acquire base stations in a Code Division Multiple Access (CDMA) system. In one embodiment, the present invention recites a method comprising several steps. First, a plurality of PN sequence values are provided internally and an input signal sample is received. The input signal sample is correlated, in parallel, with the plurality of PN sequence values. The correlation operation is performed at a rate equivalent to the input sample rate times the number of PN sequence values being correlated in parallel, assuming a resolution of one. The resultant products are respectively summed and stored in a plurality of accumulators.

Abstract: Despreading codes are switched at effective timings to perform despreading calculations by providing a rate difference between the first clock signal to input a spread signal to be subjected to the correlation detection to a data holding section and the second clock signal to switch a despreading code used to detect the correlation of the spread signal held in the data holding section.

Abstract: An improvement to a spread-spectrum receiver having a matched filter. A symbol sampler samples at the symbol time TS, a plurality of symbol samples from the matched filter. A relative-signal-level decoder decodes the plurality of received-symbol samples, generating a plurality of decoded-symbol samples. A noise sampler samples at a plurality of chip times kTC, but not at the symbol time TS, a plurality of noise samples from the matched filter, before, after, or a combination of before and after, a symbol sample. An erasure detector detects for each decoded-symbol sample from the plurality of decoded-symbol samples and from the plurality of noise samples, an erasure condition for the corresponding decoded-symbol sample, and generates an erasure signal. An erasure decoder erasure decodes the input data using the erasure signals from the erasure detector.

Abstract: A receiving apparatus comprises a receiver receiving signals via multiple propagation paths having different propagation delays and converting the signals to digital samples for processing. A channel estimator is operatively coupled to the receiver for correlating periodically selected groups of the digital samples corresponding to known symbols and periodically producing numerical estimates related to amplitudes and phases of the delayed propagation paths. A filter system filters the numerical estimates using filters periodically adapted to center frequencies of variations of the numerical estimates. A data decoder is operatively coupled to the receiver and the filter system for decoding data using the filtered estimates and the digital data.

Abstract: A synchronous detector used in a code division multiple access (CDMA) communication receiver comprises a correlator and a pre-synchronous decision circuit. The correlator calculates a plurality of correlation values between a received signal spread with an x-chip sequence of a spread code and n-chip correlation coefficients for different phase timings. The pre-synchronous decision circuit, coupled to the correlator, generates at least one timing control signal indicating a phase timing corresponding to a highest correlation value. The correlator comprises a synchronous estimator that estimates a synchronous phase by calculating the correlation values between the received signal and the n-chip correlation coefficients every cycle of the spread code and by accumulating the correlation values. The synchronous estimator comprises an n-chip correlation coefficient generator that generates the n-chip correlation coefficients at phase timings indicated by a timing control signal.

Abstract: The invention relates to a method for controlling the operation of a receiver. In the method, at least one spread spectrum modulated signal is received on at least two receiving channels, and a reference signal is formed on said at least two receiving channels by using a reference code corresponding to the code used in the modulation of the signal to be received. Further, in the method, the received signal is correlated with the reference signal. In the receiver, a set of correlators is used, and for at least one correlator of said set of correlators, a receiving channel is selected, wherein said at least one correlator is used in the correlation of the signal received on the receiving channel with the corresponding reference signal.

Abstract: A receiver for detecting spread spectrum binary data particularly on a power line in the presence of channel distortion. In one embodiment a standard pattern ideally suited for minimal distortion in the channel is used in conjunction with an alternate pattern which is developed to better detect carrier and data in the presence of certain channel distortion. The receiver switches between the standard and alternate pattern to provide improved detection. In another embodiment an adaptive pattern is used which is developed from the receive signal. For instance, the signal over several bit times is averaged to provide a pattern which is correlated with a receive signal.

Abstract: A method and apparatus for initial acquisition using an adaptive threshold includes performing a sort of a plurality of full-length correlator outputs and updating the adaptive threshold. Partial-length correlator outputs are generated and compared with an adaptive threshold. If a partial-length correlator output for a particular PN sequence timing is greater than or equal to the adaptive threshold, a full-length correlator output for that PN sequence timing is generated. A sort of a plurality of full-length correlator outputs is performed, and sort results are used to update the adaptive threshold. If a partial-length correlator output for a particular PN sequence timing is less than the adaptive threshold, a full-length correlator output for that PN sequence timing is not generated.

Abstract: An analog input signal that is sampled at a predetermined rate is multiplied by a corresponding binary code sequence, i.e. “+1” or “−1” by the multiplier. The output of this multiplier is applied in conjunction with a signal supplied by the negative feedback circuit to the analog integrator. The quantization circuit quantizes the output signal of the analog integrator into N levels and outputs a digital word. This digital word is delayed by a unit time interval by a digital delay circuit and then processed by the above mentioned negative feedback circuit. As a result of this signal magnitude reducing process, the required integrating capacitance can be minimized without risks of saturation effects. Additionally, the output is already in digital form as required by the subsequent system blocks.

Abstract: Described is a transmission system for transmitting a multicarrier signal from a transmitter (10) to a receiver (20). The multicarrier signal comprises a plurality of subcarriers. The receiver (20) comprises a channel estimator (28) for estimating amplitudes of the subcarriers and for estimating time derivatives of the amplitudes. The receiver (20) further comprises an equalizer (24) for canceling intercarrier interference included in the received multicarrier signal in dependence on the estimated amplitudes and derivatives (29). The channel estimator (28) and/or the equalizer (24) are arranged for exploiting an amplitude correlation between the amplitudes of different subcarriers and/or for exploiting a derivative correlation between the derivatives of different subcarriers By making use of this correlation the complexity of the receiver (20) can be substantially reduced.

Abstract: A vector tree correlator correlates over received samples of data spread at differing spreading rates or, equivalently, over the received samples over differing lengths of spreading sequence. When the maximum length sequence has a length N that is an integer power of 2, or 2M, then the vector tree correlator is formed from M levels. Level (1) is formed of add/subtract logic units, and Level (2) through Level (M) are formed of adders. Add/subtract logic units each receive a pair of received signal samples and combines the received signal samples based on a control signal input. The control signal input is derived from the locally generated spreading sequence. Adders of each level combine corresponding pairs of output values from the previous level. The outputs of the lower level are paired sequentially, for example, from left to right to form “groups” that may be traced downward through the tree to the corresponding received samples input to the add/subtract logic units.

Abstract: An apparatus for achieving demodulation in a radio communications system using M-sequence orthogonal modulation capable of achieving a good characteristic near the error rate characteristic obtained in the case of a synchronous detection system while suppressing an increase in the size of the hardware, including a demodulation apparatus having a reliability computing unit for computing a certainty of a value of a correlation energy as a reliability R for the correlation energy of every Walsh number, a correcting unit for obtaining a corrected correlation energy by introducing a corresponding reliability R with respect to the correlation energies, and a maximum energy selecting unit for selecting the maximum correlation energy from among obtained corrected correlation energies based on the same and demodulating a signal corresponding to a Walsh number corresponding to this maximum correlation energy as a received signal.

Abstract: An orthogonal frequency division multiplexed wideband communication system provides improved time and frequency synchronization by inserting an unevenly spaced pilot sequence within the constellation data. A receive correlates the received data using the unevenly spaced pilot sequence. The pilot sequence is generated with a maximum length pseudo random noise code and inserted into frequency bins having prime numbers.

Abstract: A cellular wireless communication network system having a plurality of base stations (1) and a plurality of mobile stations (#i) (i is an integer from 1 to N) is provided in which communication with wireless circuit is established between the respective base stations (1), and a flexibility of arrangement for the base station location is improved to realize a construction of the communication network with inexpensive cost.

Abstract: A method of correlating first and second digital signals which both contain series of numerical data values is disclosed together with a computer program, a computer-readable storage medium) and apparatus for the same. The method includes the steps of (a) sequentially calculating products of corresponding numerical data values of the first and second digital signals and providing a cumulative sum thereof; (b) upon deviation of the cumulative sum from between upper and lower thresholds levels, increasing or decreasing the cumulative sum by a predetermined amount so as to return the cumulative sum to between said threshold levels; and (c) providing a correlation parameter as a function of the number of occurrences of deviation of the cumulative sum from between upper and lower thresholds. The correlation parameter may either increase or decrease depending on whether the cumulative sum deviates above the upper threshold level or below the lower threshold level.

Abstract: The invention provides a technique for measurement of a signal to interference power ratio wherein an SIR can be measured with a higher degree of accuracy without being influenced by a fast fading environment or an inter-station interference or noise environment.

Abstract: A receiver for detecting spread spectrum binary data particularly on a power line in the presence of channel distortion. In one embodiment a standard pattern ideally suited for minimal distortion in the channel is used in conjunction with an alternate pattern which is developed to better detect carrier and data in the presence of certain channel distortion. The receiver switches between the standard and alternate pattern to provide improved detection. In another embodiment an adaptive pattern is used which is developed from the receive signal. For instance, the signal over several bit times is averaged to provide a pattern which is correlated with a receive signal.

Abstract: An apparatus and method allow receivers to quickly acquire a pseudorandom noise signal. A receiver advantageously detects frequency shifts using a compact parallel process hardware implementation of a Discrete Fourier Transform (DFT). The simultaneous detection of multiple frequencies allows the receiver to search the frequency range of the transmitted signal in larger increments of frequency, thereby increasing the speed of acquisition. One receiver does not use coherent integration before computation of the transform and advantageously maintains a flat frequency response. The flat frequency response of the DFT circuit enables searching of multiple frequency offsets without CPU intensive processing to compensate for frequency response variations. A receiver can include a Doppler correction circuit, which permits correlation data with frequency shift in the code to be non-coherently integrated among relatively fewer addresses or tap positions in memory.

Abstract: In a method of controlling a searcher used in a receiver section supplied with a sequence of baseband reception data signals divisible into a sequence of frames, a current frame rate in a current frame is used to calculate a next frame rate in a next frame following the current frame and to determine candidate slots in the next frame with reference to the next frame rate. The searcher carries out searching operation within the candidate slots in the next frame. The next frame rate is calculated so that it is not higher then the current frame rate, so as to reliably carry out the search operation. The candidate slots in the next frame may be determined by a data burst randomizer.

Abstract: A rake receiver in accordance with an exemplary embodiment of this invention is configurable by an external agent (e.g., microcontroller, DSP, or state machine) to suit the particular requirements of different spread spectrum systems. In an exemplary embodiment, the receiver includes multiple fingers. Each finger includes a plurality of generic despreaders/descramblers, a plurality of generic dechannelizers coupled to the despreaders/descramblers, and at least one timing estimation controller coupled to the despreaders/descramblers. The finger also includes at least one phase estimation controller, at least one frequency estimation controller, and at least one energy estimation controller all coupled to the generic dechannelizers.

Abstract: A receiving apparatus includes a base-band conversion circuit, a synchronizing circuit/code generator and a demodulator. The base-band conversion circuit converts a received signal into a base-band signal. The synchronizing circuit/code generator detects a spread code included in the received signal to generate a plurality of spread codes in synchronization with the spread code included in the received signal. The demodulator uses the plurality of spread codes supplied by the synchronizing circuit/code generator to demodulate the base-band signal.

Abstract: A method for synchronizing a CDMA receiver to a transmitter when an adaptive antenna is utilized to receive transmitted data, wherein a receiving antenna system is adapted between a 360° reception angle pattern (i.e., an omni-directional pattern) and a fixed reception angle (i.e., a directional pattern) by permitting the receiver to identify a pilot signal having the largest magnitude. The receiver minimizes interference from other pilot signals by steering antenna pattern nulls toward other transmitters. As a result, the time required for the receiver to acquire a valid pilot signal is significantly reduced.

Abstract: In a discrete tone system, a base station receives a transmission burst from a remote unit being installed that includes delay compensation pilot tones that are uniformly spread throughout the transmission bandwidth. The arrival time transmission burst is not synchronized with the other remote units transmitting to the base station. The base station measures the phase delay of each tone and calculates the delay of the remote unit from the slope of the line of phase angle versus tone frequency. The base station transmits a signal to the remote unit that includes the magnitude and direction of the delay, which allows the remote unit to adapt the timing of its transmission to be synchronized with the other remote units.