Abstract: A receiver for a telecommunication system, including a radio frequency unit connected to at least one antenna and configured to receive using a multitude of channels, and an estimator configured to estimate a first signal to interference and noise estimate dependent on a noise covariance matrix and channel vector, and estimate a second signal to interference and noise estimate dependent on the first signal to interference and noise estimate and a bias correction term.

Abstract: To avoid signal jamming, a method is provided for selecting a dwell channel on a receiver in a frequency hopping communication system. The method includes: measuring a noise level on channels over which a data signal is received at the receiver; selecting a dwell channel based on the estimated noise levels, where the dwell channel having the lowest noise level amongst a group of permissible channels over which to acquire a signal from a transmitter; and tuning the receiver to the selected dwell channel during a search state in which the receiver attempts to synchronize with a transmitter.

Abstract: Method and Apparatus to Perform Reactive Jamming While Simultaneously Avoiding Friendly Pseudo-Random Frequency Hopping Communications is disclosed. The system provides an enhancement to surgical reactive jammers that combines near-real-time jamming capability with the additional feature of allowing tactical communications. The jammer includes a synchronization subsystem that synchronizes jammer lockout frequencies with those frequencies being hopped to by units that are members of a friendly communications network. The synchronization subsystem is coordinated with, and therefore tied to the time-synchronized cryptography of the friendly communications net. As a result, the jammer will be aware, on a real-time basis, which frequency the friendly communications network will next be hopping to. The jammer's awareness of these future frequencies will allow those frequencies to be “locked out” of the jammer's transmission band dynamically.

Abstract: A transmitter shown in FIG. 3 inputs to a mixer 36 an IF band modulation signal generated from transmission data and a frequency hopping signal obtained by a hopping synthesizer 38 controlled by a hopping pattern generator 37, thereby obtaining a frequency hopping radio signal to be transmitted. In a receiver shown in FIG. 4, a received signal is amplified and an unnecessary wave is removed from the signal, and the resultant signal is input to a mixer 44. The mixer 44 receives an output signal of a hopping synthesizer 47 controlled by a signal obtained by adding a fixed frequency offset signal to the hopping pattern generator 45. A signal downconverted to a first IF band without frequency hopping corresponding to the offset signal with a radio frequency band signal maintaining the relative spectrum relationship appears in the output of the mixer 44.

Abstract: A method for communication includes transmitting a first uplink message from a first remote node (200, 300, 400) to a central node (100) in a wireless communication system according to a first frequency hopping scheme, and transmitting a second uplink message from a second remote node to the central node in the wireless communication system according to a second frequency hopping scheme, different from the first scheme. Both the first and the second uplink messages are received and processed at the central node.

Abstract: Frequency channel selection in a data transmission method uses a frequency hopping method. In a first method step, interference in a frequency channel is determined by detecting multiple erroneous transmissions in the frequency channel, and the frequency channel with interference is then eliminated from the frequency hopping sequence. In a second method step, the strength of external signals is measured within the frequency range of an eliminated frequency channel with interference, and the frequency channel is reinserted into the frequency hopping sequence if the strength is below a prescribed threshold value.

Abstract: A method for terminal-assisted interference control in a mobile communication system employing multi-carrier techniques such as OFDM, the mobile communication system comprising a network with a plurality of base stations controlled by a central entity, and the base stations having means for communication with user terminals located inside their cell service area, wherein the central entity schedules time-frequency groups available, for data communication purposes between the terminals and the base station, for the base stations under its control and the terminals involved in the scheduling process, each time interval.

Abstract: Disclosed herein is an Ultra WideBand (UWB) M-ary Code Shift Keying (MCSK)/Binary Pulse Position Modulation (BPPM) wireless communication system and method. The system includes a transmitter and a receiver. The transmitter selects a specific TH code using MCSK according to an additional data stream, performs BPPM on a desired signal according to the selected TH code, and transmits the modulated signal via a channel. The receiver receives the signal transmitted from the transmitter via the channel, and estimates the transmitted signal, which is transmitted from the transmitter, through detection of a Maximum Likelihood (ML) sequence.

Abstract: A method comprising: determining which of a first process and a second process uses a first resource, wherein the first process requires use of a first resource to produce a result and the second process competes with the first process for use of the first resource; and controlling the first process, when the second process uses the first resource, to produce a result without use of the first resource.

Abstract: There is provided with there is provided with a wireless communication method using a frequency hopping scheme, which performs wireless communication with a different wireless communication apparatus by using a plurality of frequency bands, including: measuring interference quantities showing strength of interference signals in respective frequency bands; selecting a hopping pattern from a plurality of hopping patterns each having hopping densities set for the respective frequency bands on the basis of the interference quantities in the respective frequency bands, the hopping densities being the number of times that transmission is performed per unit time in the respective frequency bands; notifying the different wireless communication apparatus of the selected hopping pattern; and communicating with the different wireless communication apparatus by using the selected hopping patter.

Abstract: A pre-correlation filter determines the timing of a second pseudorandom number (“PRN”) code, using an image of the average chip shape formed for a first PRN code. The filter collects measurements corresponding to samples of a received signal over multiple code chips of the first PRN code at sample times that are asynchronous to code rate. A code phase decoder directs the measurements to accumulation registers that are associated with code chip ranges that are fractions of a code chip of the first PRN code based on the code phase angles of the samples in the first PRN code, to accumulate measurements relating to chip transitions in the first PRN code and measurements relating to chip transitions in the second PRN code. The chip edges of the second PRN code are detected from the image of average chip shape for the first PRN code formed from the accumulated measurements.

Abstract: Communications among multiple nodes via a shared power line medium are carried out by dividing the available frequency spectrum in the shared power line medium into plural non-overlapping channels. A first channel is assigned to a first group of nodes, and a second channel, different from the first channel, is assigned to a second group of nodes. Communications between the first group of nodes can occur simultaneously with communications between the second group of nodes via the shared power line medium. Time slots may be assigned for the communications between the first group of nodes that occurs simultaneously with the communications between the second group of nodes via the shared power line medium. The simultaneous communications between different groups of nodes via a shared power line medium may be implemented using a frequency-hopping spread spectrum technique.

Abstract: A method and apparatus for estimating channelization codes in a wireless transmit/receive unit (WTRU) using blind code detection (BCD). A WTRU receives communication bursts and detects a midamble in the received burst. A candidate code list is generated in accordance with the detected midamble. The candidate code list includes channelization codes intended for both the intended WTRU and other WTRUs. Active channelization codes among the codes in the candidate list are identified, and the identified codes are forwarded to a multi-user detector (MUD). The present invention resolves SF ambiguity in the downlink of TSM. Since the orthogonal variable spreading factor code maintains the orthogonality between codes of different SF, SFs of other WTRUs follow the SF of the intended WTRU. Moreover, since the data for other WTRUs is not used in symbol processing after MUD, the performance of MUD for the intended WTRU is preserved with the SF ambiguity of other WTRUs.

Abstract: A frequency agile wireless response system and method of retrieving user response data from a plurality of users includes providing a base unit and a plurality of handheld response units, each communicating with the base unit over a wireless communication link using a frequency agile communication protocol. Base signals are sent with the base unit to the response units over the wireless communication link. Response signals are sent from the response units to the base unit over the wireless communication link. The base signals include a master transmission and at least occasionally include an extension transmission. The master transmission includes information establishing a time mark for the response units. The master transmission also includes information enabling the response units to receive any extension transmission associated with that base signal.

Abstract: A method and apparatus for generating a permutation for forward link hopping is provided, comprising initializing permutation constants, determining a value for p such that i is less than 2p wherein i is a first counter, initializing a second counter j to ‘0’, setting x to i+1 wherein x is index of elements of an array A, clocking a Pseudo-noise (PN) register n times to generate a pseudorandom number, setting x to p Least Significant Bits (LSB) of the pseudorandom number, incrementing j by 1, determining if x is greater than i, setting x equal to x?i, if x is greater than i, swapping the ith and xth element in the array A, decrementing counter i by 1, and mapping a set of hop-ports to a set of sub-carriers based upon the generated hop-permutation.

Abstract: A system and method for operating a communications system network, the method including operating an access point (AP) acting as a network controller in a frequency hopping network, the AP communicating with other communication devices of the network over m number of frequencies using a hopping sequence of at least some of the m number of frequencies and a dwell time d for the plurality of frequencies; and operating a communication device seeking to establish synchronized communication with other communication devices of the frequency hopping network without any cross-AP coordination, the communication device scanning all of the m number of frequencies using a scanning time s for each of the m number of frequencies; and, wherein the scanning time s is no greater than 1/m of the AP dwell time d.

Abstract: Transceiver circuitry for use in a multiple-input, multiple-output (MIMO), orthogonal frequency-division multiplexing (OFDM), communications environment, is disclosed. Error correction coding according to a fixed-block size code, such as low density parity check (LDPC) coding, is implemented. The codeword length, and codeword arrangement, are selected by determining a minimum number of OFDM symbol periods required for a payload size, and the number of available information bits in those symbol periods. A rule-based approach, for example in a table, is used to select the codeword length, and the number of codewords required. Shortening is then applied to the code, followed by determining whether puncturing or repeating of bits is necessary to efficiently use the available OFDM symbols.

Abstract: Automatic establishment of a connection between a human interface device and a host transceiver unit. A marriage ID is exchanged in a synchronization step. The marriage ID being used by both the host transceiver and the human interface device to calculate a spread spectrum modulation pattern. In one embodiment the spread spectrum modulation is a frequency hopping spread spectrum modulation.

Abstract: A method of synchronizing wireless devices includes establishing a recurring sequence of frequency channels at which the wireless devices are to communicate. The frequency channels are divided into a plurality of groups. Synchronization information is transmitted at a respective first frequency channel in each of the groups of frequency channels during a first sampling time period. One of the groups of frequency channels is selected. A wireless device is used to sample each of the frequency channels in the selected group during the first sampling time period. Non-synchronization information is transmitted after the first sampling time period. Synchronization information is transmitted at a next respective frequency channel in each of the groups of frequency channels during a next sampling time period. The next sampling time period occurs after the transmitting of the non-synchronization information.

Abstract: Provided are an apparatus and method for estimating and correcting a frequency offset in a multiband-Orthogonal Frequency Division Multiplexing Ultra-Wideband system using a time frequency hopping.

Abstract: The invention relates to a method for transmitting signals in a radio communication system consisting of at least two frequency signal-transmitting channels. At least the first (fcoord) of said frequency channels is used for organizing radio resources, and at least the second (fi) of the frequency channels is used for transmitting signals between the stations of the system where the signal transmission is carried out by the frequency channels from/in a direction of said stations in conformity with a predefined temporal pattern (P1, P2, P3).

Abstract: Disclosed is a method, system and apparatus for providing a configurable frequency hopping system that will accord with FCC mandated FHSS schemes while allowing different sensor and keypads types to communicate to a control panel or network node in the 902-928 Mhz frequency band on a single transceiver. More specifically comprising a plurality of FHSS profiles are disclosed, including a plurality of channels, each said plurality of channels having a predetermined channel spacing, a predetermined data rate, a frequency range, and a predetermined transmission power; and a FHSS determining unit for selecting an individual FHSS profile from said plurality of FHSS profiles according to a data type.

Abstract: A method and system are provided which combine (i) adaptive multi-rate half-rate transmission and (ii) intelligent frequency hopping wherein frequency hopping and intelligent underlay overlay are used simultaneously. In the latter, frequency hopping is controlled on a frequency group by frequency group basis, and one frequency hopping group is made up of one or more regular transmitters of a cell and another frequency hopping group is made up of one or more super reuse (super layer) transmitters of the cell. A wireless terminal (e.g., handset) is used in determining the carrier to interference (C/I) ratio for a received signal. A determination is then made as to whether the C/I ratio is acceptable for super layer transmission, and, if the ratio is acceptable, a super reuse transmitter operating in the superlayer range at the half-rate transmission rate is used to transmit a call to the terminal.

Abstract: A receiver is disclosed. The receiver includes a first antenna, a second antenna, a system controller, a national broadcast demodulator, a local broadcast demodulator, and an information output select device. The first antenna for receives a signal from a satellite that contains information of national interest. The second antenna receives a signal from a land-based transmitter that contains information of local interest. The national broadcast demodulator is coupled to the first antenna and the system controller. The national broadcast demodulator provides a first interrupt indicator to the system controller. The local broadcast demodulator is coupled to the second antenna and the system controller. The local broadcast demodulator provides a second interrupt indicator to the system controller.

Abstract: A correlator despreads a P/N long code constructed from two or more constituent codes A, B, C having N, M and L elements respectively. In a third stage, L filter taps decorrelate elements of the third constituent code from the input received signal, leaving elements of code AB. The outputs of the third stage delay line are summed and input into a second stage delay line having M filter taps to decorrelate the elements of the second constituent code from the input to the second stage, leaving elements of code A. The outputs of the second stage delay line are summed and input to a first stage delay line having N filter taps. The output of the first stage delay line is summed and input into a shift register. An energy peak in the shift register indicates the phase of the P/N elements in the register is proper.

Abstract: Video watermarks are added to video content to trace distribution. The video watermarks are in the form of watermarking pixels. Watermarking modules in individual computers add additional sets of watermarks to whatever initial set of watermarks are present in video content. As a result, the accumulated watermarks in distributed video content provide information on the distribution of video content.

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 communication station needs to autonomously and synchronously operate by maintaining an equal frame interval. A clock error is measured from a received packet in a wireless communication system where a beacon is transmitted periodically. This clock error is used to synchronize a counter to count the beacon's transmission/reception time and adjust a clock cycle deviation for synchronization. The synchronization is possible even in the case of restoration from a sleep state when the reference clock accuracy is poor. A period to maintain the sleep state can be extended irrespectively of the clock accuracy. It is possible to prevent desynchronization due to incorrect synchronization with an abnormal value.

Abstract: A packet detector for a multi-band orthogonal frequency division multiplexing system includes a plurality of packet detection units each corresponding to a time frequency code for detecting packets according to a spreading sequence of the time frequency code, a comparison unit for comparing correlation values provided by division units of the plurality of packet detection units, and a packet decision module for determining a time frequency code and size of a fast Fourier transform sampling window according to output signals of the comparison unit, allowing a frequency band to be selected and synchronization to be executed.

Abstract: Techniques are described for generating digital carrier multi-band user codes for a baseband ultra-wideband (UWB) signal. The digital carrier multi-band user codes comprise spreading codes that enable multiple access in a UWB system. The user codes are digital, lead to baseband operation, and provide flexibility in handling narrow band interference (NBI) within the UWB system. In one embodiment, the invention provides a method comprising generating digital carrier multi-band user codes for a baseband ultra-wideband (UWB) signal of a user in an UWB system.

Abstract: An adaptive multi-channel architecture for a wireless network is provided. A frequency hopping sequence generator module is compliant with a frequency hopping spread spectrum (FHSS) communications protocol. The frequency hopping sequence generator module is capable of performing FHSS concurrently on a plurality of communications channels. A frequency replacement module is coupled to the frequency hopping sequence generator module. The frequency replacement module is configured to receive feedback data over a feedback channel and adaptively select a transmission channel from the plurality of communications channels using the feedback data.

Abstract: A method for communication is disclosed and may include dynamically changing the bit-rate of an audio and/or video stream communicated over a Bluetooth connection based on conditions of the Bluetooth connection. A rate at which corresponding audio and/or video samples, for said audio and/or video stream, are encoded for communication via the Bluetooth connection, may be based on Bluetooth piconet event information. The bit-rate of the audio and/or video stream may be dynamically adjusting based on bandwidth of the Bluetooth connection. The bit-rate of the audio and/or video stream may be dynamically increased based on bandwidth of the Bluetooth connection. The bit-rate of the audio and/or video stream may be dynamically decreased based on bandwidth of the Bluetooth connection. The audio and/or video samples may be encoded utilizing a variable bit rate.

Abstract: A method for synchronization of transmitted and received signals in frequency hopping communications systems. A synchronization unit is arranged for synchronization of transmitted and received signals in frequency hopping communication systems and a frequency hopping communication system including a synchronization unit.

Abstract: A composite code is made for example by exclusive-OR'ing each real element of a first constituent code A with each element of a second constituent code B to obtain a basic composite code. To suppress autocorrelation, differing numbers of doping code elements are inserted between code segments made from combining each element of code A with an element of code B. A matched filter first stage removes from its input the A code and any doping code added to it, summing the elements of code A. A matched filter second stage removes from its input the B code and any doping code added at the second level. The summed elements of code B are the input to the first stage. Optionally, the summed elements of the doping code at any level may be delayed and summed with the elements of the A code in the first stage.

Abstract: A wireless product for wireless communication is constructed for spread spectrum operation within a required channel bandwidth where an RF signal for transmission in the channel is divided into sub-channels, each of which is less than the minimum channel bandwidth permitted by FCC regulations in order to realize improved transmission characteristics and greater flexibility in transmission timing and synchronization. The wireless product includes a controller for controlling system operation. During operation, the RF signal portion is less than the minimum channel bandwidth required by said regulations thus dividing the channel bandwidth to form N sub-channels, and setting the bandwidth of the RF signal to be substantially equal to the sub-channel bandwidth. The RF signal portion being transmitted in each of the N sub-channels.

Abstract: An apparatus for compensating nonlinearly distorted multicarrier signals, a multicarrier signal receiver using the same, and a method therefor are provided, where the apparatus for compensating multicarrier signals and the multicarrier signal receiver using the apparatus extract parameter information on the HPA mode from the received signal so that nonlinear distortion of the received multicarrier signal is compensated for even though an accurate transfer function of a high power amplifier (HPA) is not known and side information or a special training signal is not transmitted when a signal is transmitted, such that nonlinearly distorted multicarrier signals such as OFDM signals transmitted by an HPA having a variety of transfer functions can be adaptively compensated and therefore a demodulated signal with an improved symbol error rate (SER) can be obtained.

Abstract: Disclosed is a method for decoding received signals on communication channels between at least one transmit antenna and plural receive antennas in a space-time coded direct sequence (DS)-CDMA communication system. The decoding method includes steps of: adjusting the step-size which is an update unit for the tap weight vector for despreading received signals; updating the tap weight vector using the step-size; and despreading the received signals using the tap weight vector. According to the decoding method, the optimal performance can be achieved because the tap weight vector and the step-size are adaptively updated according to changes of communication environment. Such superior performance is more remarkable as the number of receive antennas and transmit antennas increases.

Abstract: Various embodiments are described to provide for the transmission and reception of data in an improved manner. Data transmission is improved by including in a transmitter a null generator (110) to generate an output data symbol sequence that exhibits nulls in the frequency domain at particular frequencies that an input data symbol sequence does not. A pilot inserter (120) then adds a pilot symbol sequence to this output data symbol sequence to create a combined symbol sequence. Since the pilot symbol sequence exhibits pilot signals corresponding to the nulls of the output data symbol sequence in the frequency domain, the combined symbol sequence exhibits pilots that are orthogonal to the data in the frequency domain.

Abstract: A process is disclosed for discriminating between received ranging signals, such as GPS, GNSS, and radar signals, which arrive via a single path and those which arrive via multiple paths. The number of paths is also estimated. This is accomplished by comparing the residual for an ith order ML estimator of signal time of arrival, where order refers to the number of signal paths for which the estimator is optimal, to a discriminant determined either analytically or empirically and deciding that i distinct signal path components are present in the observation of the signal if for all kth order estimators where k<i, the residual is greater than the discriminant for that order estimator and the residual of the ith order estimator is not greater than the discriminant for that order estimator. The invention is particularly useful in obtaining an appropriate signal model for model-based estimation methods.

Abstract: A system and method for transmitting data by a base station in a multiple access communication system including a plurality of sub-channels, each of which includes a predetermined number of sub-carrier bands, the sub-carrier bands being divided from an entire frequency band. The method includes the steps of: dividing input data streams in a unit of the sub-channels corresponding to each terminal into a plurality of data sequences based on a predetermined length; spreading each of the data sequences by a distinct spread spectrum code, respectively; summing and parallel-converting the spread data; hopping each frequency of the parallel-converted data in the unit of the sub-channels based on a frequency hopping pattern allocated to each of the terminals in advance; performing an inverse fast Fourier transform with respect to the hopped parallel-converted data; and transmitting the transformed data.

Abstract: The present invention relates to frequency hopping in wireless communication systems utilizing single-carriers with varying bandwidth. Frequency hopping is made possible by dividing the available bandwidth, associated to the available frequency spectrum, in a levelled structure, a bandwidth tree. By the use of a frequency hopping tree, which has the same structure as the bandwidth tree and wherein each leaf represent a hopping sequence, a frequency hopping scheme is determined. Orthogonality in-between the frequency hopping schemes for different users is ensured by letting a users hopping sequence value at a level n, be dependent on the hopping sequence value associated to the same branch structure on the adjacent level closer to the root of the tree, n?1, and an input sequence associated with the level n.

Abstract: Method and device making it possible to synchronize a master station and one or more subscriber stations in a wireless communications network, comprising at least one processor disposed at the level of each of the subscriber stations and suitable for calculating each subscriber's transmit time adjustment by taking account of the rate of variation of the satellite-subscriber path, a master station side processor suitable for measuring the loop error and a processor suitable for comparing the value of the error with a threshold value and as soon as the loop error value for a subscriber station is less than or equal to the threshold value, for giving said subscriber station permission to send its traffic.

Abstract: In a wireless communication system, a control unit (17) of a base station (1) sets a frequency hopping cycle longer than a predetermined value during a certain measurement interval in which an measurement of a frequency drift is conducted, allowing reception of a plurality of reference signals of the same frequency in receiving an uplink signal from a mobile station (2). The control unit (17) controls a reference signal extraction unit (15) and a reference signal phase difference calculation unit (16) so as to measure, based on the plurality of reference signals, the phase shift amount of a received signal at the same frequency. Thus, the wireless communication system can measure the phase shift amount by controlling the frequency hopping.

Abstract: A process control system or other system includes multiple nodes that communicate using frequency-hopping patterns. Each node may operate using its own frequency-hopping pattern. Each node may also broadcast information identifying its frequency-hopping pattern to other nodes, such as any neighboring nodes. Each node may further. receive information identifying the frequency-hopping patterns of any neighboring nodes. The nodes may then operate in a non-synchronized manner and use the frequency-hopping patterns of neighboring nodes to communicate. For example, each node may use the identified frequency-hopping pattern of a neighboring node to synchronize with and communicate data to the neighboring node. In this way, the nodes need not maintain synchronization at all times during operation. Also, different nodes may use different frequency channels at the same time, helping to increase the bandwidth available for wireless communications.

Abstract: The invention concerns a method and a system for rapidly establishing a communication, particularly a Bluetooth type communication, between at least one reader and a plurality of communicating objects. Each communicating object and said reader have a communication protocol. Each communicating object has a communication address. The method comprises: the step of defining a unique communication address for all of the communicating objects; the step, for said reader, of determining whether at least one communicating object is present in the environment in which said reader is located, by sending a request to the unique communication address of all the communicating objects; the step, for each communicating object that receives said request, of revealing its presence to said reader by sending a response signal that is time-shifted relative to the response signals sent by the other communicating objects.

Abstract: Pilot sequences are constructed from distinct “classes” of chirp sequences that have an optimal cross correlation property. Utilization of chirp sequences for pilot sequences results in pilot sequences that have optimal or nearly-optimal cross correlation and auto-correlation properties.

Abstract: Systems and methodologies are described that facilitate transmitting and receiving control data according to hopping patterns where the hopping patterns are defined based in part on bandwidth capabilities of a device transmitting the control data and bandwidth of the network on which the data is being transmitted. In this regard, devices having lower bandwidth capabilities than the network can hop within given frequency blocks reserved for control data assuming the blocks are no greater than the bandwidth of the device. Devices having greater or substantially equal bandwidth capabilities as the network can hop across disparate frequency blocks of the network reserved for control data as the device can handle substantially any hop in frequency. This preserves frequency diversity for control channels in multiple device types regardless of device bandwidth capabilities.

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 radio broadcast receiver is provided which reduces the degradation in quality of diversity-received signals. When a difference in level between a reception signal of a main antenna and a reception signal of a sub antenna is less than a predetermined threshold value, and when a difference in phase between the reception signal of the main antenna and the reception signal of the sub antenna exceeds another predetermined threshold value, a combination ratio of a combiner for combining outputs of a main tuner and of a sub tuner is set to 1:1, where in-phase combination type diversity is carried out. In other cases, the combination ratio of the combiner is switched between 1:0 and 0:1 depending on the occurrence of a multipath, where selection diversity is carried out.

Abstract: The invention provides a frequency hopping method for switching a hopping carrier frequency in a predetermined hopping pattern based on a hopping carrier table, in which there is provided intermittent receiving means for starting carrier frequency designating means every constant cycle to give a command for receiving the control channels of opposed radio base stations. In the case in which a hopping order in a hopping carrier table is skipped by n to carry out switching every intermittent receiving cycle in an intermittent receiving operation, an intermittent receiving cycle is set in such a manner that the n and a total number m of hopping carrier frequencies in the hopping carrier table have a prime relationship with each other.