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 method for receiving spectrum spreading signals using a Doppler-effect frequency-shift correction generates a corrective signal based on an estimation of a modulation period related to the Doppler effect detected in a preamble portion of a received signal. The corrective signal is used for correcting an information portion of the received signal. Base band digital signals are operated upon by using the DOT and CROSS components.

Abstract: A system and method for synchronizing and selectively addressing multiple receivers in a wireless communication system includes a spread spectrum transmitter and one or more spread spectrum receivers. The transmitter transmits a signal having an observable parameter which is pseudo-randomly varied. The receiver measures the relative times between recurrences of a selected value of the observable parameter being pseudo-randomly varied, and determines an initial state of the transmitter based upon the measured relative times. The receiver then synchronizes itself to the estimated current state of the transmitter using the determined initial state as a starting reference. In a frequency hopping embodiment, the spread spectrum transmitter comprises a feedback shift register, and transmits a sequence of pseudo-randomly hopped frequencies determined by the shift register.

Abstract: A system and method that increases the capacity of a wireless network using frequency diversity. A user switches between channels of a network using a single network interface card in such a manner that nodes desiring to communicate overlap while disjoint communications mostly do not overlap. A driver is inserted into a device's networking stack and controls the network interface card using a plurality of virtual wireless network adapters. Packets for a recipient are queued when the recipient is not accessible on the node's channel. In one embodiment where multiple nodes are switching in and out of channel, the method changes part of a nodes channel hopping schedule to ensure concurrent connectivity in a channel for at least a brief time period such that packets can be received/transmitted with desired nodes.

Abstract: A radio frequency transmitter is power controlled using a controlling system including an integrating controller, together with an inner and an outer control loop. A tracking signal supplied by the inner loop to the integrating controller of the outer loop is used to avoid windup problems when the transmitted power is saturated.

Abstract: Systems and methods for band hopping and power conservation in a wireless network are described. At least one embodiment is directed a method of hopping channels by a device within a wireless network. The method comprises hopping from a first channel to a target channel, resetting a virtual carrier sense after hopping to the target channel to enable service on the target channel, waiting for a pre-determined period of time, and setting a virtual carrier sense on the target channel after expiration of the pre-determined period of time and prior to hopping to a next target channel.

Abstract: A frequency hopping coordinator device scans a plurality of frequencies for request for services messages during an unused time slot in order to detect a request for service preamble on one of the frequencies and, responsive thereto, send a service packet message to an end device from which it received the request for service message on the one frequency. The service packet includes a current frequency sequence value of the coordinator device's pseudo-random number sequence and beacon timing information that indicates when periodic beacon messages occur. An endpoint device sends a request for services message on a first frequency of the plurality of frequencies scanned by the coordinator device that includes a preamble identifiable by the coordinator device. The endpoint device receives the service packet message and, responsive thereto, changes the end point's current frequency sequence value and timing information to match the values sent by the coordinator device.

Abstract: A method and device are disclosed for the detection and synchronization of a signal in a frequency-hopping system. The method has a step, for each frequency F(1) . . . F(M), of selecting the K samples corresponding to the greatest values of the signal, and their positions. For a given position, the M greatest values are combined which are selected from among K samples on each frequency having the given position. The greatest combined value is kept and the corresponding position. The greatest combined value is compared with a threshold value, and if the greatest combined value is greater than this threshold value, then the detection of the signal is declared.

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 of obtaining coarse synchronization in a frequency hopped/direct sequence spread spectrum (FH/DSS) time division multiple access (TDMA) data link network includes tuning the receiver to a first frequency used in the data link network. Then, signal strength of signals received on the first frequency during a sample time period is observed to obtain a sample energy pattern. An expected energy pattern during a time uncertainty window is determined based upon a known hopping pattern. Then, the sample energy pattern is compared to a first portion of the expected energy pattern, with the first portion of the expected energy pattern corresponding to a first time period within the time uncertainty window. A determination is then made as to whether the first time period is a coarse synchronization candidate based upon the comparison. If it is determined that the time period is a coarse synchronization candidate, one or more additional comparisons on different frequencies can be used to verify the hypothesis.

Abstract: A first network component of an apparatus in one example is coupled with one or more additional network components. The first network component and the one or more additional network components communicate with one another over a single, shared wireline path through employment of a plurality of code division multiple access (CDMA) codes. The plurality of CDMA codes comprise a first CDMA code and a second CDMA code. The first network component sends a first message over the single, shared wireline path to one of the one or more additional network components through employment of the first CDMA code and contemporaneously receives a second message over the single, shared wireline path from one of the one or more additional network components through employment of the second CDMA code.

Abstract: A system and method is provided for transmitting data signals and additional information signals having partially overlapping frequency bands simultaneously within a wire based communication system over the same wired medium using a spread spectrum technique for modulating the additional information signals.

Abstract: Disclosed is a method for quickly and conveniently establishing a connection between a master terminal and a slave device communicating with each other using Bluetooth. The slave device implements a special direct connection mode in which the slave device can be directly connected to the master terminal. When a user operates the slave device, the direct connection mode can be selected. The slave device notifies the master terminal of the direct connection mode. The master terminal establishes the direct connection with the slave device through paging without a slave address selection process. Since the direct connection with a target slave can be established without an address selection process, a time required for establishing a connection between the master and the slave can be significantly shortened, and also, the number of process steps can be reduced.

Abstract: The invention relates to an apparatus supporting an acquisition of a received code modulated signal by determining the correlation between the received code modulated signal and an available replica code sequence at different code phases. It is proposed that the apparatus comprises a first acquisition engine for selecting code phases which are good candidates for being the code phase at which a received code modulated signal and an available replica code sequence have the highest correlation. The apparatus further comprises a second acquisition engine for performing a refined comparison between a received code modulated signal and an available replica code sequence for each code phase selected by the first acquisition engine. The invention relates equally to a corresponding method and to a system comprising such an apparatus and a network.

Abstract: A WLAN (Wireless Local Area Network) receiver is provided that provides at least two acquisition units and at least two tracking units. The acquisition units perform a synchronization acquisition process, and the tracking units perform a synchronization tracking process. The acquisition units are arranged for being operated sequentially while the tracking units are arranged for being operated simultaneously. In an embodiment, frequency and phase error correction may be performed separately, and those units that operate at higher sampling rates may be located before lower-rate units. The synchronization process may include data-aided as well as non data-aided algorithms.

Abstract: A method and apparatus for efficiently transmitting and receiving information about spreading codes used for a packet data-transmitting channel in a spread spectrum communication system. A BS determines Walsh codes for spreading a PDCH and transmits on a PDCCH an index of a last determined Walsh code. Also, if the determined Walsh codes cannot be fully represented by the use of the last Walsh code index only, the BS transmits a Walsh space bitmap indicating the availability of the Walsh codes individually on another PDCCH or a WAICH.

Abstract: In a method and arrangement for detecting a random access channel preamble in a received uplink signal, the uplink signal is received at one or more receive antennas and contains data related to a random access channel preamble. The received uplink signal is subjected to spatial processing and temporal processing in order to detect the random access channel preamble. A best cell portion for communicating with a user may also be determined based on the detected preamble. The best cell portion represents a portion of a cell where a received uplink signal from a user has a highest signal to interference ratio. The detected random access channel preamble is indicative of the best cell portion for communicating with the user.

Abstract: A calibration method and a system for providing calibration data for use with a direction finder are provided. The method comprises providing a relative motion of a calibration receiver in a circle manner with respect to calibration transmitter at a predetermined distance from each other. The method also includes preparing and transmitting a communication frequency signal employed for transmitting a certain frequency from a list of predetermined frequencies. The preparing comprises: (a) setting a value of the dwell time ranges of the communication frequency signal to a predetermined value; (b) synchronizing in time the dwell time ranges between the calibration transmitter and the calibration receiver by using clock signals of a common synchronization source; (c) providing a hop duration time interval within the dwell time range for transmitting the frequency; and (d) generating the communication frequency signal corresponding to the frequency during the hop duration interval.

Abstract: A method is disclosed for simulating a load on an application server in a network. The method intercepts data packets of a request from a sender to a receiver. The data packets to be intercepted can be selected according to specified criteria, such as communications protocol or port and address information of the sender and/or receiver. A simulation session can begin and end based on a specified period of time or after a specified number of data packets have been received. The intercepted data packets are stored in a buffer and the time of arrival of the data packets is recorded. The data packets are held in the buffer for a user specified delay time. Upon expiration of the delay time, the data packets are forwarded to the receiver. Alternately, the method can operate bi-directionally, or by intercepting and delaying data packets of a response of the receiver sent to the sender.

Abstract: Systems and techniques are disclosed wherein a gated pilot signal can be acquired by producing a plurality of product values for each of a first and second signal and a generated signal, coherently combining portions of the product values produced from the first signal and noncoherently combining those coherently combined portions to produce a first value, coherently combining portions of the product values produced from the second signal and noncoherently combining those coherently combined portions to produce a second value, and noncoherently combining the first and second values.

Abstract: A communication system includes a receiver having a variable gain module and a baseband processor. The baseband processor measures the power of the signal received and derives a variable gain control setting that is inversely proportional to the power of that signal and sends the variable gain control setting to the variable gain module. The baseband processor generates a channel quality metric that is equivalent to the normalized geometric mean of the squared magnitudes of the gain estimation, divided by the total noise-plus-interference power.

Abstract: A wireless data communication unit (700) shares a data communication resource with a plurality of other data communication units. The wireless data communication unit (700) receives channel status information from a wireless serving communication unit on an outbound channel (100) and transmits data to the wireless serving communication unit on an inbound channel. The wireless communication unit includes a processor (708) for monitoring channel status symbols inserted on the outbound channel, such that the processor (708) regulates time intervals between successive data transmissions (480) on the inbound channel dependent upon the monitored channel status symbols inserted on the outbound channel. A method of sharing a communication resource is also described.

Abstract: An apparatus and method for performing digital timing recovery includes a rotating demultiplexor receiving a four times oversampled baseband signal and providing four downsampled phases at respective outputs. Each output is processed by a correlation detector which computes a peak sum signal for each downsampled phase. The peak sum signals are processed to produce a best phase select output signal. The best phase select output signal is used to select the optimum sampling phase. Symbol timing is then determined based on the relative peak offset in the best downsampled phase.

Abstract: Determination of the impulse position in a multipath channel in a noisy environment includes dynamically adjusting a threshold value when making comparisons against a signal property level.

Abstract: The method of this invention for preparing a profile in W-CDMA which, using a timer value and norm value, helps a mobile unit to synchronize its signals with those of a base station, comprising providing a profile data preparing portion which cumulatively adds a new norm value to a previous cumulative value fetched from a profile memory to cause the result to be stored as a current cumulative value in a profile memory and repeat the same cumulative addition each time a new norm value is fed to said portion; furnishing the profile data preparing portion with an overflow detection ability to detect the overflow of the profile memory; and choosing, when the overflow of the profile memory is detected, a maximum writable value of the profile memory, and causing the profile memory to store said maximum writable value as a current cumulative value.

Abstract: A method for improving gap coverage in data collection in an automatic meter reading system is disclosed that reduces overall system cost while improving data collection. A transceiver in the system receives data from a plurality of meter modules via encoded reader transmitters (ERTs, or endpoints) and transmits the received data to a central utility database that assigns a unique identification code for each of the meter modules in the system. Data collected via the endpoints is transmitted to the central utility database and correlated with identification codes in the utility database to determine which endpoints did not respond. A data collection error is assigned to the endpoint from which data is not received by the central utility database and a receiver module is then positioned adjacent the endpoint assigned the data collection error to improve data collection.

Abstract: With the object of accurately reproducing, by means of a small-scale circuit, differences in propagation delay at antennas of received signals that are received as input by way of each of a plurality of receivers, frequency data generator 6 supplies frequency data that contain a frequency component that is synchronized in common to the plurality of receivers 2-1 to 2-n. At receiver 2-n, local oscillation signal generator 3-n, which is represented by a D/A converter, generates a local oscillation signal from frequency data that have been synchronized in common. The passing phase of a received signal that is outputted from antenna 1-n by way of receiver 1-n is thus fixed, and as a result, the phase difference of received signals that are received by DSP 8 by way of the plurality of receivers 2-1 to 2-n becomes the propagation delay difference of the received signals.

Abstract: A remote unit transmits data by Frequency hopping over a set of frequencies to a base station. A plurality of antennas at the base station receives the transmitted frequency hopped data. An optimal combining of each antenna's received hopped data for a particular frequency is determined. Data is selectively transmitted using the plurality of antennas from the base station to the remote unit over the particular frequency. The selectively transmitting is selected using the optimal combining.

Abstract: A WLAN (Wireless Local Area Network) receiver having a synchronization unit is provided. The synchronization unit comprises a first functional unit for performing a first signal processing function, a second functional unit for performing a second signal processing function different from the first signal processing function, and at least one signal processing circuit. In the synchronization unit the first functional unit is operating at least one of the signal processing circuits for performing the first signal processing function, and the second functional unit is arranged for operating the at least one signal processing circuit operated by the first functional unit for performing the second signal processing function. Since the above-described signal processing circuits or modules can be re-used for the antenna diversity unit and the preamble detection unit this results in a smaller number of gates and an improved density of the circuitry.

Abstract: The invention provides methods and apparatus for multiple user detection (MUD) processing that have application, for example, in improving the capacity CDMA and other wireless base stations. One aspect of the invention provides a multiprocessor, multiuser detection system for detecting user transmitted symbols in CDMA short-code spectrum waveforms. A first processing element generates a matrix (hereinafter, “gamma matrix”) that represents a correlation between a short-code associated with one user and those associated with one or more other users. A set of second processing elements generates, e.g., from the gamma matrix, a matrix (hereinafter, “R-matrix”) that represents cross-correlations among user waveforms based on their amplitudes and time lags. A third procesing element produces estimates of the user transmitted symbols as a function of the R-matrix.

Abstract: A method is disclosed for obtaining a spreading code set for a code division multiple access (CDMA) communications system. The method includes (a) generating a P?×P? spreading code set where P?=P/N, where P is the spreading gain in chips/symbol and where N is an integer multiple of 2; and (b) replicating chips in each spreading code by N to produce a P?×P spreading code set. The step of generating may include randomizing the spreading code set by performing at least one or row or column permutation. The P?×P spreading code set is subsequently loaded into system hardware for operating the system hardware with a bandwidth that is less than the bandwidth that would be required to operate with the P?×P? Hadamard spreading code set. The CDMA system may be a synchronous, direct sequence code division multiple access communications system.

Abstract: Several techniques are provided for use by wireless devices to avoid interference with signals that are of a periodic or quasi-periodic nature that may operate in the same frequency band and proximity. In some cases, the periodic signals are detected and their timing is determined so as to predict when a next interfering event will occur. Devices that are affected by the periodic signal (such as an affected device with information to be transmitted or devices that have information to be transmitted to the affected device) are controlled to prevent transmissions during the interfering intervals. In addition, a process is provided to dynamically fragment a transmit frame of information to transmit part of the information before the interfering interval and the remainder of the information after the interfering interval, rather than waiting to transmit the entire frame until after the interfering interval.

Abstract: In a security system, a method and apparatus for two-way frequency hopping communications between the control panel and each peripheral device which maintains channel synchronization through the assignment of fixed beacon frequencies for the transmission of synchronizing data. The use of frequency hopping provides high immunity to jamming and interference, reduced occurrence of multi-path phenomena, and allows for transmissions at a much higher output power than conventional fixed-frequency communications, to thus increase the effective range of the peripheral devices while providing effective and reliable two-way communications between the control panel and the peripheral devices. The invention also provides a large number of channels, which allows for actuators such as sirens, strobes and line seizing devices to be wireless in addition to sensors.

Abstract: Components and method are provided to efficiently process wireless communications data where prior knowledge of the specific format of the communication data is not available. A wireless transmit receive unit (WTRU) is configured for use in a wireless communication system where communication data for selected channels is transmitted in system time frames in formats selected from among a set of predefined formats. The WTRU has a receiver, a memory, a received chip rate processor (RCRP), a format detector and a de-interleaver. The RCRP is preferably configured to despread each wireless signal of spread data received in each time frame using a minimum spreading code or other appropriate key sequence and to store resultant despread data for each respective time frame in the memory. The format detector is preferably configured to determine the number of physical channels and the respective spreading factor for each physical channel for the wireless signal of spread data received in each time frame.

Abstract: The present invention relates to a method of synchronisation between communication networks exchanging information by frame of informations, each communication network having clock and the number of clock pulses is monitored by a counter. The synchronisation is made by reading information representing the counted clock pulses of the clock of the first network at the appearance of a reference event, inserting at least said information or calculated information on the basis of said information into the frame of information as the synchronisation information, transferring said frame of information from the first to the second network, reading information representing the number of counted clock pulse of the clock of the second network at the appearance of reference event, reading synchronisation information inserted in received frame of information from the first network, calculating a difference between information and synchronising the second network.

Abstract: The present invention allows many of the benefits of spatial diversity to be realized in a hopping radio communications system. One embodiment of the invention includes transmitting signals from a first radio using a first hopping sequence and transmitting signals from a second radio using spatial processing and a second hopping sequence. The second hopping sequence is coordinated with the first hopping sequence. In another embodiment, the invention includes selecting a set of spatial processing parameters based, at least in part, on a determination whether a third radio using a first frequency resource during a first time interval uses a second frequency resource during a second time interval and transmitting a signal from a first radio to a second radio during the second time interval using the second frequency resource and the selected set of spatial processing parameters.

Abstract: A method for controlling antennas of a receiving device in a radio system, especially in a mobile radio system, in which at least one change is made using a frequency hopping method between a number of transmission frequencies that are provided for the transmission of radio signals. A table is formed with data relating to the reception quality of each antenna. This data is evaluated on each change to the transmission frequency, and one of the antennas is selected as a function of the result of the evaluation. The method is especially suitable for use in systems using slow frequency hopping methods (slow frequency hopping systems), such as bluetooth or WDCT systems.

Abstract: Symbol 102 that is spread with the only short spreading code and inserted in synchronism with a long spreading code is specified by detecting the correlation with only the short spreading code. Next, another short spreading code indicative of a timing of reverse and forward link switching is specified, where the short spreading code is multiplexed at the same position as that of the detected symbol. The detection of the symbols spread with only these spreading codes enables to acquire synchronization of the long spreading code, synchronization of switching of reverse and forward links, and synchronization of a transmission frame. It is thereby possible to reduce synchronization acquisition time for the long spreading and an easy planning of base station locations without decreasing the frequency utilization efficiency.

Abstract: An over-sampling circuit is provided at a front stage of a digital matched filter, and a received signal is over-sampled with it. Synchronous acquisition of the received spread spectrum signal is implemented by adding the data obtained by the over-sampling, inputting it into the digital matched filter, and then performing a correlation thereon.

Abstract: A spread-spectrum phase-locked loop clock generator includes a PLL circuit, a modulation generator, a bit stream processor and a multiplexer. The modulation generator outputs a bitstream in response to an input signal and a control signal. The bitstream processor generates bitstream signals. The multiplexer outputs one of the bitstream signals in response to a frequency deviation control signal. The PLL circuit is controlled by the output of the multiplexer.

Abstract: A method for the acquisition of burst synchronization signals in a spread spectrum communication system is provided. The method receives a burst synchronization signal, applies a dwelling procedure according to a scheduling scheme to the burst synchronization signal, wherein the dwelling procedure calculates a matched filter output, sums the outputs over one slot time, calculates the energy in the sum, searches the maximum energy value and passes it to a Random Access Memory. At the end of the scheduling scheme, searching is performed for the overall maximum energy value among the energy values stored in the Random Access Memory.

Abstract: A method for receiving spectrum spreading signals with frequency shift correct in which the modulation period related to the Doppler effect is estimated by using a preamble and a correction signal is elaborated, the signal transmitting the information is then corrected by this correction signal.

Abstract: Techniques to avoid interference with a frequency hopping signal that are of a periodic or quasi-periodic nature that may operate in the same frequency band and proximity with other devices. For example, the frequency hopping signals may be transmitted by Bluetooth devices operating in the same frequency band as IEEE 802.11 WLAN devices. When a frequency hopping interfering signal is detected, sufficient knowledge of the frequency hopping sequence is derived without obtaining state of a frequency hop sequence from information carried in the frequency hopping signal. This knowledge is used to predict or determine when future transmissions of the frequency hopping signal will be present in a particular frequency channel of concern.

Abstract: A wireless spread spectrum communication system for transmitting data includes a plurality of end point transmitters and at least one receiver. The end point transmitters transmit data via a frequency hopped spread spectrum signal where the transmitting signal is sent without the benefit of frequency stabilization. The receiver is responsive to the frequency hopping spread spectrum signals and includes a correlator and a signal processor. The correlator samples at least a first portion of a preamble of the signal and correlates the portion of the preamble with a known preamble pattern to determine a probability of correlation. The signal processor applies a Fast Fourier Transform algorithm to the signal in response to the probability of correlation to track a narrowband frequency of the signal based on at least a second portion of the preamble and to decode data encoded within the signal subsequent to the preamble.

Abstract: A shared memory architecture for a GPS receiver, wherein a processing memory is shared among the different processing functions, such as the correlator signal processing, tracking processing, and other applications processing. The shared memory architecture within the GPS receiver provides the memory necessary for signal processing operations, such as the massively parallel processing, while conserving memory cost by re-using that same memory for other GPS and non-GPS applications. The shared memory architecture for a GPS receiver provided in accordance with the principles of this invention thereby significantly minimize the costly memory requirement often required of extremely fast signal acquisition of a GPS receiver.

Abstract: A low-cost, flexible, high performance system and method comprises a means for interfacing a code division wireless system to a fast packet-switched network for transmission over a core network to a destination terminal user via a destination access node and a destination access radio port.

Abstract: The frame synchronizing circuit establishes frame synchronization by detecting a sync pattern laid in an incoming frame. The frame synchronization circuit comprises a first frame synchronizing unit and a second frame synchronizing unit. The first and second synchronizing units synchronize with a first pattern, a second pattern at a first position and a second position, respectively. Thereafter, when the first position used for the synchronization by the first frame synchronizing unit is found to be in error, the first frame synchronizing unit synchronizes with the second pattern at the second position used by the second frame synchronization unit.

Abstract: A highly integrated GPS RF Front End which uses a single conversion stage employs an image rejection mixer stage to eliminate the need for an image reject RF bandpass filter. Also a relatively high sample rate A/D is employed which allows a timeless monolitic IF Filter to be used. The disclosure also discusses a GPS Front End topology that is easily integrated from industry standard building blocks. With the broad variation in potential receiver designs, the present invention includes some specific receiver topologies that lend themselves to a high level of integration. The specific designs presented here are comprised of industry standard building blocks and functions that have been described elsewhere in the related art.

Abstract: A method for estimating symbol sequences from multiple transmitters which communicate with common receivers sharing the same medium is disclosed. This invention can be used in wireless communications and wireline communications such as in cable modem sys terms and digital subscriber loops to speed up joint detection of symbol sequences of multiple transmitters to achieve low error probability. For convenience, only applications of this invention to wireless communications employing multiple antennas are described herein. The requirement for matrix operations like matrix inverses increase with the logarithm of the number of symbols instead of the number of symbols as with techniques based on Cholesky decomposition.

Abstract: A system and method for narrowing the range of frequency uncertainty of a Doppler shifted pilot signal in a satellite or other communications system with relative signal source and receiver motion. The satellite communications system includes a user terminal (for example, a mobile wireless telephone), a gateway (terrestrial base station), and at least one satellite with unknown position and unknown relative velocity. The method includes the steps of shifting the pilot signal over a plurality of frequency hypotheses, coherently accumulating samples of the pilot signal over a plurality of chips, measuring the energy of the accumulated pilot signal samples, accumulating the energy measurements over a plurality of chips to produce an energy accumulation value, and determining which of the plurality of frequency hypotheses results in the highest energy accumulation value.