Abstract: A receiver is provided that can shorten the time during which initial synchronization is established. When the frequency of an output signal from the PLL 12 is set to the receiving channel corresponding to the transmission channel for a transmission signal, the time-constant switching circuit 17 changes the time constant of the loop filter 14 to a low rate mode. Meanwhile, the output signal frequency from the PLL is swept between the highest frequency and the lowest frequency signal of a frequency channel. Thus, a receiving channel corresponding to the transmission channel is estimated by signals received during the sweeping period so that the initial synchronization is established based on the estimation result. Receiving-channel estimation, to which adverse effects due to multi-path fading are reduced, can be reliably performed by selecting each of plural receiving antennas in time-divisional mode and synthesizing envelopes of received signals from respective antennas.

Abstract: A receiver unit includes a first buffer that receives and stores digitized samples at a particular sample rate and a data processor that retrieves segments of digitized samples from the first buffer and processes the retrieved segments with a particular set of parameter values. The data processor is operated based on a processing clock having a frequency that is (e.g., ten or more times) higher than the sample rate. Multiple instances of the received signal can be processed by retrieving and processing multiple segments of digitized samples from the first buffer. The receiver unit typically further includes a receiver that receives and processes a transmitted signal to provide the digitized samples and a controller that dispatches tasks for the data processor. The data processor can be designed to include a correlator, a symbol demodulation and combiner, a first accumulator, and a second buffer, or a combination thereof.

Abstract: A base station receives a signal resulting from multiplexing a communication signal spread using a signal-specific spreading code and sent by mobile station apparatus and a calibration (CAL) signal spread using a signal-specific spreading code and sent for each unit frame for a predetermined time by a CAL radio signal generator in a same frequency band. An A/D conversion/despreading section and an A/D conversion/despreading section extract the communication signal and CAL signal from the received signal. A calibration processing section carries out calibration processing using the CAL signal in parallel with a communication using the communication signal. An array combining/signal processing section carries out demodulation processing on the communication signal using the calibration processing result.

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 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 mobile terminal 11 and a base station 12 use a first communication channel (i.e. a transmission route 21) to conduct communication relating to a first call. A first time (i.e. switching time) and a second time (i.e. switching-back time) during the communication are determined, and when the switching time is reached, communication using transmission route 21 is ceased and attempts are made to establish spreading code synchronization in order for mobile terminal 11 and base station 12 to commence using a second communication channel (i.e. a transmission route 22) to conduct communication relating to both the first call and a second call. If synchronization cannot be established before the switching-back time is reached, attempts to establish synchronization are ceased, and mobile terminal 11 and base station 12 recommence using transmission route 21 to conduct communication.

Abstract: A method (700) and a mobile station (160) for reporting multi-path signals based on minimum separation are described herein. The mobile station (160) may include a list with a first energy/position pair corresponding to the energy parameter and the position parameter associated with a first multi-path signal of a synchronization code. The mobile station (160) may generate a second energy/position pair corresponding to the energy parameter and the position parameter of a second multi-path signal. The mobile station (160) may detect the position parameter of the second energy/position pair being within a minimum separation associated with the position parameter of the first energy/position pair. The mobile station (160) may also detect the energy parameter of the second energy/position pair being greater than the energy parameter of the first energy/position pair. Accordingly, the mobile station (160) may replace the first energy/position pair on the list with the second energy/position pair.

Abstract: An inverted-code generator 41 inverts the PN code sequence into an inverted code sequence. The inverted code sequence is transmitted. The inverted code sequence, which is transmitted as a communication breaking wave, is formed into a code sequence in the form if inversion of a pilot signal conforming to CDMA system. Moreover, the phase of the inverted code sequence has been advanced. Therefore, the pilot signal, which is being propagated, can appropriately be compensated with the advanced inverted code sequence. Thus, a fact can be recognized by a portable telephone that the portable telephone is deviated from a communication area for the base station.

Abstract: A multipath mitigation method consists of locating a multipath-invariant (MPI) point of an ideal autocorrelation function and measuring the distance between the MPI point and DLL. The same MPI point is located in a received correlation function, and the distance between the point and the DLL, now affected by multipath, is measured. The difference between the ideal distance and the actual distance is the code tracking error resulting from multipath. The error is subtracted from the computed pseudorange or used to control the DLL. The method can be used to reduce the effects of all types of tracking error sources, such as signal transmission failure or code noise.

Abstract: The method and device enable determining the carrier frequency of base stations in the mobile receiver of a cellular mobile radio system working with W-CDMA. The carrier frequency of the primary synchronization channel of the strongest received base station is first searched for by carrying out a non-coherent correlation of the received signal with the primary synchronization code over a very large number of code elements of the signal.

Abstract: A programmable band-pass filter in a radio-frequency receiver. The band-pass filter has a bandwidth substantially covering a channel bandwidth. Once the appropriate channel in use is determined, the frequency band of the band-width filter is set to correspond to it.

Abstract: A wireless receiver (UST). The receiver comprises at least one antenna (ATU) for receiving a plurality of frames (FR) in a form of a plurality of paths. Each of the plurality of frames comprises a plurality of time slots (SLN), and each of the plurality of time slots comprises a plurality of symbols. Further, each of the plurality of paths has a corresponding sample position, wherein the plurality of symbols comprise a primary synchronization code symbol (PSC). The receiver further comprises circuitry (52) for correlating a primary synchronization code across a group of the plurality of symbols, and circuitry for identifying a plurality of path positions within the group. Each of the plurality of path positions corresponds to a respective one of a plurality of largest-amplitude paths represented within the group as detected in response to the circuitry for correlating.

Abstract: A method of acquiring signal code phases includes selecting a correlation sum with a greatest magnitude from a set of correlation sums after a predetermined time has elapsed. A geographic positioning receiver performing the method includes two or more memory banks (114, 116, 118, 120) alternating between storing a signal sequence and transmitting the signal sequence to parallel correlators (132, 134) to be correlated against a predetermined pattern sequence for real-time data processing.

Abstract: A method is disclosed for receiving transmitted signals in the presence of CW interference in a communication system that determines the presence of a code in a received signal by comparing with a detector threshold calculations made in accordance with a sample of a received signal. Such systems include but are not limited to those incorporating a Sequential Probability Ratio Test. The method includes obtaining a first input power value of the received signal at a first sample time and obtaining a second input power value of the received signal at a second sample time. The first and second power values are compared in order to provide an input sample comparison and the forgoing steps are repeated in order to provide a plurality of input sample comparisons. The detector threshold is adjusted in accordance with the plurality of sample comparisons. The CW signal can be strongly correlated with a short code used for the acquisition purposes.

Abstract: A threshold tracking loop (TTL) (400) for detecting the time of arrival of a spread spectrum wireless communication signal includes a pseudo-noise (PN) generator (440) for generating a receive PN code for use in spread spectrum decoding and a series of time delay units (401-408) for adjusting a phase offset of the PN code. A first PN despreader (423) is coupled to the time delay units and PN generator for despreading an early pilot signal (413). A second despreader (425) is coupled to the time delay units and PN generator for despreading a late pilot signal (415). A first comparison circuit (443) is coupled to the first PN despreader for comparing a signal value of the early pilot signal with a preselected threshold value (322) and for advancing the PN code phase offset if the early signal value is greater than the threshold value.

Abstract: A rake architecture for a frequency division duplex (FDD) and use also in TDD and TD-SCDMA type communications system, designed to significantly reduce the memory capacity required and thereby also reduce an area on the die of an application specific integrated circuit (ASIC) into which the memory is integrated. A single circular buffer, preferably of the shared memory type is shared by all of the rake fingers of a rake receiver to significantly reduce the hardware and software required to time align multipath signals received by a UE from a base station. This unique time alignment technique also reduces the number of code generators required to track a plurality (typically three) of base stations.

Abstract: A code division multiple access communication system receiver includes block-based chip timing estimation. A chip timing estimate is generated from samples of a received signal by performing an averaging operation over a designated block of chips in each of first and second legs of an early-late synchronizer. The chip timing estimate is determined as a function of an error signal corresponding to the difference between outputs of the first and second legs, and is utilized to adjust a code generator clock or to otherwise control chip timing in the receiver. In an illustrative embodiment, a separate block-based chip timing estimator is implemented in each of the fingers of a Rake receiver.

Abstract: A loop error detector for use in a Pseudo Noise (PN) code timing tracking loop is disclosed. A first multiplexer receives an early I-channel signal and an early Q-channel signal, and alternately selects the received early I and Q-channel signals at a ½-chip period. A first accumulator accumulates the early I and Q-channel signals multiplexed by the first multiplexer for a specific chip period. A second multiplexer receives a late I-channel signal and a late Q-channel signal, and alternately selects the received late I and Q-channel signals at a ½-chip period. A second accumulator accumulates the late I and Q-channel signals multiplexed by the second multiplexer for the specific chip period. An operator calculates a sum and a difference of the early and late I-channel signals accumulated by the first and second accumulators, calculates a sum and a difference of the early and late Q-channel signals, and multiplies the sums by the differences.

Abstract: An apparatus comprising a first stage and a second stage. The first stage may have a first plurality of states connected by a first topology. The second stage may have a second plurality of states connected by a second topology. The second topology may be different from the first topology.

Abstract: A digitally sampled spread spectrum signal is received, despread, and accumulated at a center frequency lower than the sampling rate and higher than zero.

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 control method of searching for a neighboring cell of a mobile station communicating with a base station is provided in a direct sequence CDMA mobile communication system which transmits information by carrying out double modulation using a first spreading code group and a second spreading code. The first spreading code group includes spreading codes that have a same repetition period as an information symbol period and are used in common by the base stations, and the second spreading code has a repetition period longer than the information symbol period. The base stations are assigned different second spreading codes.

Abstract: A method of providing time tracking between a first signal and a second signal in a communication device. In one embodiment, a first signal is generated by the communication device and a second signal is received from an outside source. Then correlation data between a first signal, at a plurality of timing conditions, and a second signal is generated by hardware. Next, the correlation data is filtered by software or firmware at a plurality of timing conditions. Afterward, the correlation data is compared to a threshold value to evaluate accuracy of a system timing for the first signal to obtain a result. Finally, the system timing for the first signal is corrected based upon said result of the comparing step.

Abstract: A frequency hopping receiver capable of real time demodulation, and a method thereof are provided. The frequency hopping receiver includes first and second frequency generators, a switch, a controller and a demodulator. The first frequency generator receives a first frequency control signal according to a predetermined control and generates a predetermined frequency first carrier wave used to generate a synthesized carrier wave for demodulating the received signal. The second frequency generator receives a second frequency control signal according to a predetermined control and generates a predetermined frequency second carrier wave used to generate the synthesized carrier wave for demodulating the received signal. The switch switches between the first and second carrier waves in response to a signal for selecting a carrier wave, to generate a continuous synthesized carrier wave.

Abstract: A receiver for use in a spread spectrum communication system includes the following components: an acquisition system configured to detect a transmitted spread spectrum signal by simultaneously correlating multiple search phases of a reference spreading signal against an output from a receiver channel; a demodulation system configured to recover data embedded in the spread spectrum signal by simultaneously correlating the spread spectrum signal with multiple possible data phases of the reference spreading signal over consecutive data periods; and a bank of correlating devices configured for use both in the acquisition system and in the demodulation system.

Abstract: A wireless network includes master and slave units. The master sends a master address and clock to the slaves. Communication is by means of a virtual frequency hopping channel whose hopping sequence is a function of the master address, and whose phase is a function of the master clock. Transmitted inquiry messages solicit slave address and topology information from the slaves, which may be used to generate a configuration tree for determining a route for a connection between the master and slave units. Slave address and topology information may include an own address from each of the slave units and only first order address lists from each of the slave units. Generating the configuration tree involves generating a hierarchy of connectivity rings from the first order address lists. Each connectivity ring may be generated in accordance with a rule that a higher-numbered connectivity ring cannot include nodes representing units that are already represented by a node in a lower-numbered connectivity ring.

Abstract: A spread spectrum wireless device (100) may include a receiver (110), a searcher (128), a search controller (130) and other features. The search controller (130) selectively generates control signals to control the searcher (128), which searches for a spread-spectrum signal. In one embodiment, the architecture of the searcher (128) is dynamically configurable by the search controller (130) to selectively search multiple channels using multiple frequency bins for the signal.

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: A technique is used in a data terminal (110, 160) that encodes and decodes a data packet that is transmitted in a link of a frequency hopping system. During encoding, an information portion of the data packet is determined for transmission, a transmit redundancy check code is generated over the information portion and an identifier using a predetermined redundancy check code generator, and the data packet is generated to include the transmit redundancy check code and the information portion, but exclude the identifier. During decoding, the information portion and a received redundancy check code of the received data packet are determined, a calculated redundancy check code is generated over the information portion and the identifier, using the predetermined redundancy check code generator, and the information portion is rejected when the received redundancy check code does not match the calculated redundancy check code.

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: A pilot phase tracking loop for an OFDM receiver including a phase rotator for receiving an incoming signal, which is coupled to a Fourier transform, which is coupled to a pilot phase error metric for determining a phase error estimate associated with a received OFDM symbol, e.g., a data symbol. The pilot phase error metric is coupled to a loop filter, which is coupled to an oscillator, which is coupled back to the phase rotator. The phase rotator rotates the incoming signal by the filtered phase error estimate for subsequent OFDM symbols to reduce the phase noise of the signaling output from the phase rotator. Thus, the phase noise introduced by a radio portion of the OFDM receiver and an OFDM transmitter is compensated for by the pilot phase error estimation in the baseband portion of the OFDM receiver and improved OFDM signal tracking is accomplished under poor SNR conditions.

Abstract: This invention relates to a method for data transmission in two-way communication via low-voltage systems that are linked to a higher order telecommunication network. Data transmission takes place within the low-voltage system at a high-frequency range of up to 30 MHz using band spreading of data signals and a transmit level below the specified radio interference or noise voltage limit, in that said band-spread data is given a direction coding to specify a logical direction within the low-voltage system using different sequences of a family of pseudo-random numbers to enable multiple-user operation, and in that the binary sequences of data with their user-specific spreading and direction-specific coding are identified by correlation using specified sequences at attenuation-dependent intervals within the low-voltage system, then said data sequences are regenerated and assigned new direction codes for forwarding.

Abstract: A pilot phase tracking loop for an OFDM receiver including a phase rotator for receiving an incoming signal, which is coupled to a Fourier transform, which is coupled to a pilot phase error metric for determining a phase error estimate associated with a received OFDM symbol, e.g., a data symbol. The pilot phase error metric is coupled to a loop filter, which is coupled to an oscillator, which is coupled back to the phase rotator. The phase rotator rotates the incoming signal by the filtered phase error estimate for subsequent OFDM symbols to reduce the phase noise of the signaling output from the phase rotator. Thus, the phase noise introduced by a radio portion of the OFDM receiver and an OFDM transmitter is compensated for by the pilot phase error estimation in the baseband portion of the OFDM receiver and improved OFDM signal tracking is accomplished under poor SNR conditions.

Abstract: The present invention is directed to providing frequency hopping medium access control among a plurality of nodes (e.g., communication stations) in a wireless communication system. The present invention is directed to decentralized control of synchronization among the plural nodes. In accordance with exemplary embodiments, a node used to control synchronization of the communication system can switch from a first master node to a second master node.

Abstract: A method is disclosed for receiving a transmitted signal in a communication system employing CDMA techniques wherein the transmitted signal includes a plurality of short codes, each of which is transmitted repetitively over a fixed period of time and where the received signal has CW interference in addition to the transmitted signal. The method includes using a Sequential Ratio Probability Test (SPRT) for detecting the presence of the short code in a plurality of time phases of the received signal by calculating a likelihood ratio for each phase. A likelihood ratio is a comparison of the signal's Probability Distribution Function (PDF) with a background noise PDF. The background noise PDF is calculated by combining in the RAKE the current short code with the input signal.

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 a 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 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 a 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 method for reducing interference and a radio system where a signal spreadcoded by digital pseudo noise is used for communication are provided. As the delay distribution of the signals of subscriber terminal equipment at base stations is great and thus the mutual interference of the signals may also be great, the base station adjusts the phase of the spreading codes of the subscriber terminal equipment so as to reduce interference. The method and the radio system enable high data rates and reduce the calculation required for interference correction.

Abstract: A convolutional despreading method takes advantage of the algebraic structure of the spreading code and applies convolutional type decoding to received signal chip symbols to rapidly estimate code phase, preferably used for rapid acquisition of direct sequence spread spectrum signals. Modeled reduced-state structures having branchword transitions are used to reduce metric computations. The reduced state structures and algebraic structures provide additive constraints for modifying convolutional sequential metric searching for improved speed of code phase determination. The convolution despreading method preferably uses a modified convolutional sequential search algorithm, such as, a modified Fano Tree convolutional sequential search, or, a modified Viterbi trellis convolutional sequential search. The method can also directly determine a modulated data stream, when present, to provide demodulated data without necessarily performing conventional cross correlation despreading.

Abstract: A method and apparatus for detecting spectrum spread signals by reducing the correlation between the main information signal and the spread signal as much as possible, whereby the detection of a spectrum spread signal is made easier. From an input signal, in which a spectrum spread signal obtained by spectrum spreading an additional information signal has been superimposed on a main information signal, the spectrum spread signal is detected. Using a level adjusting circuit, the gain of the input signal, mainly the main information signal is controlled to reduce the change in the main information signal, or the input signal is sliced at a predetermined level by a slicing circuit to fetch a signal at a predetermined level or lower.

Abstract: Users or subscribers of a spread spectrum synchronous communications system provide signals to the central station or base unit of that system, and receive signals therefrom. Proper synchronization among those users (and their signals) is needed to ensure proper operation of the system. To ensure proper synchronization among those users, the signal produced by each user is checked for presence and amount of any offset error. This is accomplished by using three despreaders for the signal for each user. For one such user, each such despreader for that user receives the spreading code for that user. However, the spreading code as received by any one such despreader is time-delayed with respect to the spreading code as received by the other two despreaders. Each such despreader receives the spreading code with a different amount of delay imposed on that spreading code. The outputs of the three despreaders are digitally combined (e.g. compared), or compared, to produce the offset estimate for that user.

Abstract: A despreading circuit which can reduce a circuit scale and power consumption is described. The circuit includes an A/D converter which converts a CDMA modulated analog signal to a digital signal of N bits, and a searcher which detects a synchronization phase from high-order small bits of the N bits and outputs synchronization phase information to a control circuit. The control circuit transmits a signal for allowing despreading to be performed to a sliding correlator based on the phase information. The sliding correlator despreads the N bit digital signal outputted by the A/D converter and outputs the resulting correlation output as a despreading signal.

Abstract: A receiving system or a received radio-wave estimation method is provided that can maintain received field strengths at a nearly uniform level under multipath conditions. The antenna switch 41 can select outputs of four antennas at high speed (where n=4). The high-frequency amplifier 42 amplifies the output of the antenna switch 11 and the demodulator 42 demodulates amplified signals. The matched filter bank 45, surrounded with chain lines, receives a demodulated signal, for example, the I-phase component. In the matched filter bank 45, the phase shifter &phgr; shifts respective signals output from four delay elements (r1, r2, r3, and r4). The adder (Ka, . . . , Kp) synthesizes the phase-shifted signals and then supplies the maximum matched output to the maximum level selector 46.

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.

Abstract: GNSS receiver includes a subsystem that reduces the adverse effects of multipath signals on punctual and early-minus-late correlation measurements by making the correlation measurements using a “blanked-PRN code.” The blanked-PRN code is all zeros except for adjacent positive and negative short pulses that occur at every code bit transition in a locally-generated PRN code. Using the blanked-PRN code, the receiver makes non-zero correlation measurements only near the code bit transitions in the local PRN code. If the local PRN code and the PRN code in the received GNSS satellite signal are closely aligned, the non-zero correlation measurements are made at the times of the bit transitions in the received PRN code.

Abstract: Test hopping frequency data stored in the hopping frequency data table 35b is set in the hopping table 26 as a data setting signal w. Digital test data is transmitted while hopping the carrier wave frequency among the frequency candidates which correspond to the hopping frequency data thus set in the hopping table 26. Frequency candidates which have attained high recognition rate for the test data are selected as a carrier wave hopping pattern, and are set in the hopping table 26. Bi-directional communication will be performed thereafter while the carrier wave frequency hops according to the hopping pattern.

Abstract: A frequency-hopping communication system preempts certain burst frequency assignments. The communication system is capable of communicating to mobile stations (114, 115) via a radio channel (121) in a TDM/TDMA mode. A plurality of mobile stations are assigned burst frequencies for transmission during timeslots of the TDMA system. To support additional mobile stations without additional burst frequencies, the communication system preempts the burst frequency assignment from the plurality of mobile stations, and utilizes the preempted assignment to support communication to the additional mobile stations.

Abstract: A method for synchronization of a receiver to a direct sequence spread spectrum (DS-SS) signal in a telecommunications system. A verification process is performed in the receiver upon initial detection of a first DS-SS signal prior to attempting synchronization to a second signal. In the verification, a window search is performed in a window centered on the PN phase of the initially detected first signal. A number K of search passes are made, each on M PN offsets. At least one parameter for each of the K window search passes is saved. The at least one parameter from each pass is then processed according to a predetermined algorithm. Based on the results of the algorithm, a decision is made as to whether or not to attempt synchronization to the second signal or to restart the search.

Abstract: A cellular radio system in which a base station receiver can receive, on the reverse link, data from a mobile terminal in one of four control modes. In the first mode, the mobile terminal sends an independent user pilot, not synchronized with the base station, on the reverse link and the user data channel is synchronized to this independent user pilot. In the second mode, the mobile terminal slaves its user pilot to the pilot it receives from the base station and the user data channel is synchronized with this slaved user pilot. This second mode allows the user terminal to receive round trip delay information for purposes of geolocation and rapid reacquisition. In the third mode, the mobile terminal slaves its user pilot to the incoming base station pilot, as in the case of mode two, but the user data channel operates in the orthogonal mode using the ranging information received from the base station. The phase relationship between the user pilot channel and the user data channel is calibrated.

Abstract: The present invention is an apparatus and method thereof for performing frequency hopping communication with another party over a subset of hopping frequencies from available frequencies. The spectrum is arranged into a plurality of segments, with each segment corresponding to a subset of the spectrum of frequencies, preferably a contiguous subset of the spectrum. The apparatus includes a communication device for communicating with another party. The communication device receives data over a used segment from a plurality of the segments and signal strength data indicating a current reception power level for the hopping frequency from the other party. A processing unit analyzes the received data to determine an occurrence or non-occurrence of an error over the used segment and notifies the other party to modify the current transmission power level for that used segment according to the occurrence or non-occurrence of an error, via said communication means.