Abstract: Increased data communication capacity in a sector of a CDMA wireless system using a combination of code division multiplexing and time division multiplexing. Adjacent subsectors may transmit carrier signals having the same frequency and using the same Walsh codes may be used by imposing a partial offset of the sector PN sequence.

Abstract: Remote control signaling may be conveyed using a spread spectrum link and/or a non-spread spectrum link. Enabling link interfaces (such as corresponding transmitters, receivers, or transceivers) to support this flexibility are provided in a shared housing and couple as appropriate to a remote control signal platform. A corresponding apparatus may comprise a housing having disposed therein a first radio frequency transmitter such as a spread spectrum transmitter and a second radio frequency transmitter such as a non-spread spectrum transmitter. This housing can further contain a remote control signal controller that operably couples to at least one of the first and second radio frequency transmitters. As another example, a corresponding apparatus may comprise a housing having disposed therein a first radio frequency receiver comprising a spread spectrum receiver and a second radio frequency receiver comprising a non-spread spectrum receiver.

Abstract: A method for providing a fast fading channel in a MIMO communication system is disclosed. The method includes encoding a series of source data to generate a first plurality of encoded output signals and multiplying the first plurality of encoded output signals by a plurality of random complex numbers to generate a second plurality of encoded output signals, and transmitting the second plurality of encoded output signals via the corresponding plurality of antennas, wherein the transmitting signals vary in time and frequency independent of the channel conditions.

Abstract: A frequency estimation method of multiband (MB)-orthogonal frequency division multiplexing (OFDM) ultra wide band (UWB) system using an Alt-PHY time frequency (TF) hopping strategy based on IEEE 802. 15. 3a. includes the steps of: a) selecting a predetermined number of frequencies among a plurality of center frequencies based on a predetermined number of OFDM symbols and estimating relative frequency offsets for selected frequencies; b) obtaining an average relative frequency offset by averaging the estimated relative frequency offsets when two or more frequencies are selected at the step a); and c) obtaining real frequency offsets for each of the center frequencies by transforming the obtained average relative frequency offset to the real frequency offsets and compensating a frequency offset caused by a transmitting/receiving local oscillators based on the obtained real frequency offsets.

Abstract: A signal analyzer to characterize the RF signal transmitted by a frequency hopping radio transmitter. The transmitted signal is analyzed while hopping across a broad frequency band without knowledge of the hop frequencies, timing or signal bandwidth. A wide range of signal parameters are measured on the dehopped signal to characterize the radio performance and the compliance to the radio specifications.

Abstract: A plurality of communication bursts are transmitted substantially simultaneously in a time slot of a time division duplex/code division multiple access communication system. The communication system has a maximum number of K midamble shifts. Each burst has an assigned midamble. Each midamble is a shifted version of a basic midamble code having a period of P. A combined signal is received. The combined signal includes a received version of each of the communication burst's midambles. A P by P square circulant matrix is constructed including the K midamble shifts. A channel response is determined for each of the K midamble shifts using a prime factor algorithm (PFA) discrete Fourier transform (DFT) algorithm, the received combined signal and the P by P square circulant matrix. The PFA DFT algorithm has a plurality of stages. Each stage has P inputs.

Abstract: Methods and apparatus are provided for establishing a connection between a scanner device and a pager device over a sequence of hop channels. The scanner device is repetitively activated and a hop channel is selected from the sequence of hop channels as a function of a present phase. A determination is made as to whether the selected hop channel is a forbidden hop channel. A substitute hop channel is selected from the sequence of hop channels as the selected hop channel if the selected hop channel is a forbidden hop channel. The selected hop channel is monitored for receipt of a paging message during the present phase.

Abstract: A novel MODEM and method of operating a MODEM usable in spread spectrum communication utilizing multiple waveforms in orthogonal spread signals imbeds a tracking signal in one of the spread signals for efficient tracking by a receiver so that both spread signals can have wideband characteristics. Therefore, one spread signal contains a tracking channel and a wideband channel, allowing for higher order modulation in the wideband channel for transmitting information, while still providing good tracking features. The second spread signal is an orthogonal wideband channel serving as the main high data rate conduit. In the preferred embodiment, the first portion of the waveform (in the first spread signal) is modulated using Bi-Bi-Phase Shift Keying (Bi-BPSK), while the second portion of the waveform (in the second spread signal) is modulated using Multiple Phase Shift Keying (MPSK). The two waveform portions are Time Division Multiplexed (TDM) at the chipping rate.

Abstract: Frequency synthesis is implemented by providing a delta-sigma modulated signal associated with a selected frequency, which frequency can vary based on a selection input. The delta-sigma modulated signal is converted from the digital to analog domain. The delta-sigma modulated signal can be provided directly from memory based on the selection input or, alternatively, it can be provided by a signal generator and processed by a delta-sigma modulator to provide the delta-sigma modulated signal. The selected frequency can be varied at a high rate of speed.

Abstract: A network system includes a network having a network bus, such as unshielded differential twisted-pair wires, electrically connected to a plurality of remote devices, and a network controller for digitally directing transmissions with the remote devices via the network bus. The network system also includes a plurality of network device interface elements adapted to interconnect the network controller with respective remote devices via the network bus. Each network device interface element includes a local oscillator, and is capable of transmitting and receiving messages via the network bus. To at least partially limit electromagnetic emissions from the local oscillator, each network device interface element further includes a spread-spectrum clock. And to further aid in limiting electromagnetic emissions, each network device interface element can further include a suppression assembly.

Abstract: The present invention discloses a low power spread spectrum transceiver capable of preserving power while selectively initiating data transmissions under a preferred spread spectrum protocol. The transceiver, while in a power preserving deep sleep mode, uses DSSS circuitry to periodically monitor a predetermined wideband frequency for a spreading code of a DSSS signal from a remote receiving unit. Upon receipt of the appropriate spreading signal, a limited data transmission can be initiated. The DSSS signal contains information that can be decoded and utilized to switch out of DSSS receiving mode and into FHSS communication or transmission mode, or an FHSS session can be initiated automatically upon receipt of an appropriate wake up signal. While in FHSS mode, FHSS encoded data at the end point device's transceiver is communicated to the remote receiving unit. At the completion of the data transfer, the transceiver returns to low power sleep mode and recommences DSSS monitoring.

Abstract: The invention relates to an asynchronous transfer mode method of transmitting digital signals in which terminals (16, 18) send to the same station (20). Calls are transmitted by cells (40, 42, 44, 46), the terminals send successively in separate periods (60, 62, 64, 66; 70, 72, 74), and each cell is assigned at least two orthogonal codes (C1, C2, C3, C4). In accordance with the invention, the duration of the period during which each terminal sends and/or the number of codes assigned to each terminal and/or the number of symbols assigned to a particular code in a terminal can be selected on each sending as a function of a particular power level (80).

Abstract: A vehicle communication system uses one or more components to process both narrow band signals and spread spectrum signals. A spread spectrum-like signal is generated from the narrow band signal. The spread spectrum-like signal is processed as a spread spectrum signal.

Abstract: A wireless communication network that generally establishes a source node transmit window (during which a type A node transmits signals) and a source node receive window (during which the type A node receives signals). The node may then transmit over a CDMA link during the source node transmit window to a destination node. Similarly, the source node receives over the CDMA link from the destination node during the source node receive window. The duration of the source node transmit and source node receive windows may be of any duration. Type B nodes adopt the opposite transmit and receive timing as a type A node after assimilation. The network provides a technique for assimilating new nodes, in which new nodes transmit their own reservation channels in a handshaking sequence, and CDMA spreading codes are assigned until all available spreading codes are in use.

Abstract: A transmitter for a mobile communication system based on an OFDM scheme and a method for controlling the same. The transmitter can implement a characteristic of a multiple access scheme based on an OFDM scheme, a characteristic of a CDMA scheme, and a characteristic of a frequency hopping scheme which has very strong resistance to the frequency selective fading.

Abstract: The present invention is directed to a frequency hopping spread spectrum transceiver. The transceiver includes a microcontroller; a transmitter having a voltage controlled oscillator, a direct digital synthesizer, and a power amplifier; and a receiver having an amplifier, a mixer, an IF amplifier, a demodulator, and a data slicer. When transmitting, the transmitter communicates a preamble over a predetermined number of preamble channels, and thereafter communicate groups of data bytes that each comprise a subset of the data message over a predetermined sequence of data channels. When receiving, the receiver investigates the predetermined number of preamble channels to search for the preamble and tests the received bits to insure that the preamble and a start frame delimiter have been properly received to synchronize the receiver with the transmitter.

Abstract: A radio transmission method is useful for transmitting or receiving control data and useful data. Prior to modulation onto a carrier frequency, the control data is transformed from a format adapted to a first radio transmission method into a format adapted to a second radio transmission method. In addition, a radio transmission system includes a baseband module and a high-frequency section, the baseband module and the high-frequency section being designed for radio standards which differ from one another, for transmitting useful data using control data. The radio transmission system also includes an adapter circuit which is suited for transforming the control data of the one radio standard into control data of the other radio standard.

Abstract: A wideband code division multiple access (CDMA) communication system overlayed on an IS-95 network generates two or more digital bit streams from a group of wideband digital data streams, each digital bit stream spread to form a CDMA component signal. Each CDMA component signal is combined with a corresponding IS-95 digital bit stream to form a composite CDMA signal, allowing a base station to share transmitter subsystems between the wideband and IS-95 systems. For up to three carrier frequencies, up to three composite CDMA signals are employed. A digital bit stream for a group of summed user conversations in the IS-95 system modulates a respective RF carrier frequency to generate a low-power RF signal. The CDMA component signals of the wideband CDMA system are generated so each has a chip rate identical to the chip rate of the digital bit streams of the IS-95 system.

Abstract: A radio transmission system including many radio transmitters using frequency hopping carriers to intermittently transmit very short messages indicative of status of stimuli associated with the transmitters. The transmitters transmit transmissions independently of a receiver receiving the transmissions and independent of each other. In operation, radio transmitters transmit messages at varying frequencies at time intervals that can be varied as well. The frequency and time intervals are varied according to patterns that can be determined individually for each transmitter. A receiver holds data indicative of the future transmission frequency and time for each transmitter and updates the data based on the time and the content of the received messages. In addition, a simple method is provided to generate a very large number of orthogonal frequency-time hopping sequences that are individual for each transmitter and based on the transmitter ID.

Abstract: A hybrid data frame is presented for a time division multiple access frequency hopping communications system. The frame includes uplink and downlink subframes, and each subframe includes a plurality of frequency hops. First frequency hops in each subframe have at least one time slot, and the first hops follow default non-adaptive frequency hopping patterns, such that unsynchronized communicating units can synchronize with the communications system during the first hops using the predetermined default pattern. The second frequency hop also includes at least one time slot, and employs an adaptive frequency hopping pattern. Once a communicating unit is synchronized to the communications system via the first frequency hop, it can be assigned to a time slot within the second hop and adaptive frequency hopping interference avoidance techniques can be implemented.

Abstract: A system and method for resource management and traffic control in time division duplex communication systems is discloses. A multi-radio base station maintains communication links with a plurality of remote terminals, each of which requests a specific bandwidth ratio. A controller analyzes the requested bandwidth ratios and allocates slots in the base station radios according to a packing scheme that synchronizes the transmission and receive timing of the multiple base station radios communication links.

Abstract: A method, and a system of mitigating interference effects under a communication environment including a first spread spectrum (SS) transmission scheme and a second spread spectrum (SS) transmission scheme in the same frequency band are proposed in this present invention. Firstly, responsive to a received signal, output number of signal of the first SS transmission scheme and the second SS transmission scheme. Secondly, retrieve the timing, phase and amplitude information of signals of the first SS transmission scheme in the received signal, and the timing, phase and amplitude information of signals of the second SS transmission scheme. Generate a plurality of linearly-modulated signals based on a predetermined manner, correlate the received signal based on the plurality of linearly-modulated signals to generate a correlated outputs.

Abstract: A transmission system using frequency and time spreading techniques is disclosed. The transmission system allows priority of transmission parameters and adjustment of same in relation to transmission quality and channel characteristics measured in real time.

Abstract: The present invention relates to a digital pulse generator being adapted to be integrated in electronic equipment, such as hearing instruments, mobile phones and/or audio equipment. In particular, the present invention relates to a digital pulse generator being capable of providing an output signal on two or more terminals. The digital pulse generator according to the present invention requires a minimum of electrical components, so as to provide a cheaper and easier assembling process, and to provide a digital pulse generator that is shock resistant.

Abstract: A power control bit inserting method between a base station and a terminal. The base station and the terminal each use a plurality of adjacent frequency bands as signal paths with independent signal paths of a real part and an imaginary part given to each frequency. In the power control bit inserting method, a unit time is set to a power control group period, n-bit data is allocated to each signal path, the power control group period is divided by the number of signal paths, and a power control bit is inserted in each divided segment, so that the insertion positions in the real and imaginary parts of each frequency are spaced from each other by n/2 bit and the start position of the real signal path of each frequency is inserted at an appointed bit position of the corresponding frequency.

Abstract: A method and apparatus are described for applying a narrow band FH link for low-rate and medium-rate communications, and a stationary wide band channel for high-speed (HS) communications. A master and one or more slaves sharing the same FH link may form a piconet. Master and slaves may hop synchronously according to a pseudo-random hop sequence. A master may control traffic on the FH link. An HS link can be established between a master and one or more slaves or between two slaves. An appropriate band of the radio spectrum is selected adaptively based on lowest RSSI measurements both in master and slave to establish the HS link without making use of a hopping scheme. A master shares its time between the HS slave on the HS link and the slaves remaining on the FH link using Time Division multiplexing. If the HS link uses a part of the band over which the piconet hops, the master controls the traffic such that the HS link is never visited by the FH link.

Abstract: The present invention relates to methods and systems for wireless communication wherein a plurality of narrowband carrier frequencies is overlaid with at least one wideband carrier frequency. In particular, the present invention relates to maintaining radio communication on the narrowband carrier frequencies closest to the edge of the bandwidth of the wideband carrier frequency in order to reduce system interference. This is accomplished by using frequency hopping to preferentially switch radio communication to narrowband carrier frequencies closest to the edge of the bandwidth of the wideband carrier frequency. Thus, the present invention discloses systems and methods which allow several communication devices to occupy the same frequency spectrum while maintaining interference at acceptable levels.

Abstract: A “software” radio in the form of a system is completely configurable and controllable in real-time by software and has a coordination capability to enable scaling to network aggregate data rates in the 10s of megabits per second per base station with no interference among the multiple radios. Base stations can, in turn, be time and frequency coordinated. Scalability is provided by the addition of substantially identical relay radios at each base station. A hybrid spread spectrum method and system of the invention include a protocol which facilitates coordinated frequency hopping. The system does not dwell more than a few milliseconds at any frequency center to achieve high scalability of the system in, for example, a metropolitan area. A single coaxial cable feeds control signals, electrical power signals and RF signals to a microwave antenna to reduce system hardware and installation costs.

Abstract: A system for communicating between computers that are at a number of different locations in a large multi-story building in which radio transmission is achieved through stairwell shafts and through windows along a zone outside of the building. This system employs communication through spread spectrum transceivers and a set of directional antennas. At each station, one of the antennas is circular polarized and the other is linear polarized with a horizontal electrical component to facilitate reflection off the floors of the building. The spread spectrum is a hybrid frequency hopped and direct sequence modulated signal.

Abstract: A “software” radio in the form of a system is completely configurable and controllable in real-time by software and has a coordination capability to enable scaling to network aggregate data rates in the 10s of megabits per second per base station with no interference among the multiple radios. Base stations can, in turn, be time and frequency coordinated. Scalability is provided by the addition of substantially identical relay radios at each base station. A hybrid spread spectrum method and system of the invention include a protocol which facilitates coordinated frequency hopping. The system does not dwell more than a few milliseconds at any frequency center to achieve high scalability of the system in, for example, a metropolitan area. A single coaxial cable feeds control signals, electrical power signals and RF signals to a microwave antenna to reduce system hardware and installation costs.

Abstract: A highly reliable and high-speed data transmission is made by using an FH or MFSK mode as suitably selected according to the usage of channels. When a reception signal is entered into a receiver through a transmission line, (i) a signal processing unit supplies the spectrum intensity values of carrier frequencies, (ii) a channel detection unit controls the phase of a time slot based on the spectrum intensity values, selects the MFSK or FH modulation mode, and supplies reception code data corresponding to detected carrier frequencies, and (iii) a decoder supplies reception information data based on the reception code data.

Abstract: A small and lightweight base station transceiver utilizes a plurality of low-powered time division duplexing switches instead of a single high-powered time division duplexing switch. The base station transceiver includes a forward signal path, a reverse signal path, and a plurality of time division duplexing switches being switchable to the forward signal path or the reverse signal path according to a time division duplexing timing control signal generated from a time division duplexing timing controller. The plurality of time division duplexing switches corresponds to N time division duplexing switches where the symbol N represents a number. Output signals of the time division duplexing switches are filtered in a plurality of N bandpass filters, coupled in a junction coupler, and then radiated in the air through first and second antennas.

Abstract: A random pulse type radar apparatus sends out as an output signal a spectrum spread radio wave including a pseudo random signal-less period and receives echoes in this signal-less period to thereby significantly reduce transmission peak power.

Abstract: A physical channel assignment method prevents the same logical channels from being always adjacent to each other on a frequency axis so that any interference between the adjacent channels can be averaged. By using the values of first pseudo-noise codes as the channel numbers and assigning the physical channels (f1 to f7) to the first logical channel (#1); obtaining second pseudo-noise codes whose phases are shifted from those of the first pseudo-noise codes; and using the values of the second pseudo-noise codes as the channel numbers and assigning the physical channels (f1 to f7) to the second logical channel(#2), the first and second logical channels (#1, #2) can be prevented from being always adjacent to each other on the frequency axis.

Abstract: In a radio system that employs frequency hopping (FH), access time delay is reduced, without compromising processing gain, by adding direct-sequence (DS) spreading to the system. This results in a hybrid FH/DS system, wherein the use of DS spreading permits a reduction in the number of hop frequencies used during start-up. Once synchronization is achieved, pure FH spreading, rather than the hybrid FH/DS spreading, along with a greater number of hop frequencies are used.

Abstract: An improvement to a code-division-multiple-access (CDMA) system employing spread-spectrum modulation, with the CDMA system having a base station (BS) and a plurality of remote stations. The base station has a BS-spread-spectrum transmitter and a BS-spread-spectrum receiver. A remote station has an RS-spread-spectrum transmitter and an RS-spread-spectrum receiver. The BS transmitter transmits a broadcast common-synchronization channel, which includes a frame-timing signal. The broadcast common-synchronization channel has a common chip-sequence signal, which is common to the plurality of remote stations. In response to the RS-spread-spectrum receiver receiving the broadcast common-synchronization channel, and determining frame timing from the frame-timing signal, an RS-spread-spectrum transmitter transmits an access-burst signal. The BS-spread-spectrum transmitter, responsive to the BS-spread-spectrum receiver receiving the access-burst signal, transmits an acknowledgment signal.

Abstract: A radio system is disclosed for supporting a greater number of users than can be supported in a conventional CDMA system that supports multiple users. The radio system is a hybrid system combining elements of conventional spread spectrum techniques. The system may be defined as a parallel hopping hybrid direct sequence (DS)/slow frequency hopping (SFH) code division multiple access (CDMA) system in combination with a DS/CDMA system, frequency hopping (FH)/CDMA system and a multi-carrier system.

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 first master transceiver (102) of a first wireless network monitors (602) neighboring wireless networks to discover a strongest interfering master transceiver in one of the neighboring wireless networks. The first master transceiver then time-aligns (604) hop intervals of the first master transceiver with the hop intervals of the strongest interfering master transceiver to ensure that a transmission of the strongest interfering master transceiver during each hop interval used by the strongest interfering master transceiver cannot interfere with the transmission of the first master transceiver during more than one hop interval of the first master transceiver, thereby minimizing the probability of self-interference between the first wireless network and the one of the neighboring wireless networks.

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 method for use with a computer system includes modulating a first clock signal according to a first frequency-time profile to generate a second spread spectrum clock signal. The first clock signal is modulated according to a second frequency-time profile that is asynchronous to the first frequency-time profile to generate a third spread spectrum clock signal.

Abstract: A universal radio having adjustable communication parameters such that the radio can communicate in different DS or FH type systems as well as DS-FH hybrid type systems which employ both DS and FH spread spectrum techniques. The radio is included in a mobile terminal and/or base station and can be adjusted by the user to employ communication parameters relating to various different cellular communication systems. Thus, the mobile terminal and/or base station can be used in combination with the cellular communication systems provided by different manufacturers.

Abstract: A radio system is disclosed for supporting a greater number of users than can be supported in a conventional CDMA system that supports multiple users. The radio system is a hybrid system combining elements of conventional spread spectrum techniques. The system may be defined as a parallel hopping hybrid direct sequence (DS)/slow frequency hopping (SFH) code division multiple access (CDMA) system in combination with a DS/CDMA system, frequency hopping (FH)/CDMA system and a multi-carrier system.

Abstract: A radio transmission system including many radio transmitters using frequency hopping carriers to intermittently transmit very short messages indicative of status of sensors associated with the transmitters. In operation, a time interval generator included in a transmitter generates pulses activating the transmitter at time intervals according to a predetermined algorithm. When activated, the transmitter transmits a message at one or several different frequencies. The frequencies are changed according to a predetermined algorithm and differ for each subsequent transmission. Alternatively, when an abnormal sensor status is detected, the transmitter transmits repeated messages at a plurality of predetermined alarm frequencies for a predetermined time regardless of the time interval generator.

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.

Abstract: The present invention is an apparatus and method thereof for performing frequency hopping (FH) communication with another party over an available spectrum of frequencies. The spectrum is arranged into a plurality of segments, with each segment corresponding to a subset of the frequencies, preferably a contiguous subset of the frequencies. The FH communication apparatus includes a communication device for communicating with another party. The communication device receives data over a sequence of hopping frequencies from the other party, with each of the hopping frequencies being part of a used segment from the plurality of segments. A storage device stores an error value for each used segment. A processing unit identifies a reception error in the received data and an erred segment in which the reception error occurred. The processing unit modifies the error value associated with the erred segment accordingly.