Abstract: A method for automatic address assignment is disclosed, said method being based on a distance measurement, a master (M) transmitting via the bus a preamble (P) which is received by all the slaves which are to be addressed. The slaves react to the preamble (P) by transmitting a response signal sequence (A). A slave (S2) which is located upstream, in the direction of the master (M), of a slave (S3) which transmits a response signal sequence (A) registers the response signal sequence (A) of the slave (S3) and subsequently waits for a new preamble (P). The slave (Sz) which does not register any response signal sequences (A) from other slaves is the last slave (Sz), seen from the master (M), without address allocation on the bus. This slave (Sz) switches into a state in which it is ready to receive an address-assigning telegram (T) from the master (M), with which address-assigning telegram (T) it is assigned an unambiguous address.

Abstract: A multiple access communication network is disclosed having a primary station that is coupled via a transmission medium to a plurality of secondary stations. The primary station is arranged for determining a free channel list comprising the channels, which are not used by any of the secondary stations to transmit information to the primary station. The primary station transmits this list of free channels to the secondary stations. The secondary stations are arranged for attempting to seize one of the channels indicated on the free channel list. If the attempt to seize a channel was successful, the secondary stations keeps using the channel it seized until it has all available information transmitted. If the secondary station stops using the channel, the primary station will include the channel again in the free channel list.

Abstract: The data communications rates on a communication line between a central office (CO) and a customer premises equipment (CPE) modem are set by initially attempting to synchronize at a base upstream and downstream rate. The CO then requests that the CPE modem send upstream a signal to noise ratio (SNR) indication and, based on this, predicts the maximum attainable downstream rate. An attempt is then made to synchronize on this new rate. If successful, then, the CO reads the upstream SNR and based on this attempts to maximize the upstream rate. Line quality is then monitored and adjusted as necessary.

Abstract: An optimum combiner that reduces the amount of interference imposed upon a first base station by transmissions of other base stations within the same communication system. Two antennas are used to receive transmissions within a receiving station. A rake receiver is coupled to each antenna. By optimally combining the signals that are received by each independent finger of the rake receiver, interference that is correlated between a finger associated with the first antenna and a finger associated with the second antenna can be minimized with respect to the desired signal. Optimum combining requires determination of optimum combining coefficients. A max-ratio combining algorithm may be substituted for the optimal combining algorithm depending upon interference characteristics.

Abstract: A traffic channel transmission device for a CDMA communication system using a plurality of coding rates and orthogonal codes, determines a present channel condition and adaptively selects a coding rate and an orthogonal code according to the determination. In the device, a channel receiver receives a channel signal and a controller analyzes the received signal to decide an environment of a channel in service and generates a coding rate select signal and orthogonal code information according to the decision result. A channel transmitter includes a channel encoder for encoding transmission data at a coding rate selected according to the coding rate select signal and an orthogonal modulator for generating an orthogonal code according to the orthogonal code information to spread the encoded data with the generated orthogonal code, whereby the channel transmitter adaptively encodes and spreads the transmission data according to the channel environment.

Abstract: In accordance with exemplary embodiments of the invention, throughput and capacity in a TDMA system are increased using several different channels all operating simultaneously on the same carrier frequency. In a first embodiment, a base station in a cell in the system simultaneously transmits a different information sequence from each antenna of a transmitter, on the same carrier frequency. Mobile stations in the cell each receive the signals from the base station antennas as a composite signal, and then use known synchronization information to extract a desired information sequence from the composite signal. In a second embodiment, the different information sequences are all intended for the same mobile station, which uses the synchronization information to extract each sequence from the composite signal. In a third embodiment of the invention, the base station simultaneously transmits identical information sequences to a mobile station via different antennas.

Abstract: A controllable mechanism for by-passing Layer 4 (L4) classification is based on the insertion into a set of Layer 3 (L3) rules in an L3 lookup tree set of Layer 4 (L4) Classification Required Flags. The state of the L4 classification flag is set by comparing the L4 classification rule to an IP (Internet Protocol) lookup rule. Routing is accomplished by selecting which rule to apply to the data packet and reading the state of the corresponding L4 Classification Required Flag. In response to a first state of the corresponding L4 Classification Required Flag, an L4 classification is performed followed by a routing of the data packet. In response to a second state of the corresponding L4 Classification Required Flag performing a routing of said data packet. In a second embodiment, the method inserts into a set of L3 rules in L3 lookup means a set L4 Classification Required Flags and Global Flags.

Abstract: A plurality of Integrated Devices are provided with an Internet connection and a telephone number. The Internet connection has an associated Internet protocol (IP) address permanently or dynamically assigned. It is initiated when one device calls the telephone number of a called device via telephones on a public service telephone network (PSTN). The telephone number has associated telephone connectivity via a telephone line, such that the Integrated Devices can be connected to by dialing the associated telephone number via telephones on the PSTN. An Internet connection is associated with the calling device; the called device is an Integrated Device. An IP address for a first one of the calling or called devices is obtained and provided to the other device, which initiates an Internet connection therewith by sending an Internet message to the IP address thereof.

Abstract: A telecommunications system comprising one or more cross-connects and a plurality of telephone exchanges. Two or more of the telephone exchanges are arranged to communicate with each other via the one or more cross-connects. An adapter provides the telephone exchanges with inter-communication via the one or more cross-connects. The adapter converts traffic between packetized and non-packetized form.

Abstract: An asynchronous serial crosspoint switch is word synchronized to each of a number of transceiver circuits. The crosspoint switch circuit generates both a master bit clock and a master word clock signal. A transceiver circuit recovers the master bit clock signal from an incoming high-speed serial data stream using a clock and data recovery circuit. The recovered bit clock signal is used as a timing signal by which data is serialized and transmitted to the crosspoint switch circuit. The data stream transmitted to the switch circuit is frequency locked to the master bit clock signal, such that the serial data stream need only be phase adjusted with a data recovery circuit. To recover word timing, the switch circuit issues alignment words to the transceivers during link initialization. The transceivers perform word alignment and establish a local word lock. Alignment words are then reissued to the switch circuit using the local word clock.

Abstract: A packet transfer apparatus for transferring data packets between devices connected to a bus includes a receiving circuit connected to the bus for receiving a packet from the bus and a transmit circuit, also connected to the bus, for forming and placing a transmit packet on the bus. A header identification circuit, connected to the receiving circuit, detects a packet header of the received packet and determines if the packet header indicates a DMA transfer operation. A first buffer is provided for storing the packet data when the packet header indicates a DMA transfer and a second buffer is provided for storing the packet data when the packet header does not indicate a DMA transfer. A memory is connected to the first buffer and stores the packet data it receives from the first buffer. The memory also transfers stored data to the first buffer. A DMA controller is provided to control a DMA operation between the memory and the first buffer.

Abstract: In packet communication paths that include header compression, header fields of packets to be communicated are altered. The alteration of the header fields does not disturb their functionality, and is transparent to the header compression scheme of the packet communication path. The altered header fields are provided for compression by the header compression scheme, resulting in improved performance of the header compression scheme. Performance improvements can also be achieved in packet communication paths that do not use header compression, by violating the integrity of header fields in packets to be transmitted over the packet communication path.

Abstract: A device for classifying input data based on the values of first and second data of the input data includes a content addressable memory having one or more rows. A first row includes first and second memories, first and second comparators, and a first hit line. The first memory stores second minimum and maximum values defining a second range. The first and second comparators determine whether or not the first and second data fall within the first and second ranges, respectively. The first hit line outputs a first logic value when the first data falls within the first range and the second data falls within the second range. Conversely, the first hit line outputs a second logic value when the first data falls outside the first range or the second data falls outside the second range.

Abstract: A method and apparatus retrieves and stores configuration information for network endpoint devices from other devices in the network, such as a switch adjacent to the endpoint device. When the endpoint device establishes a connection with the network, it generates a sequence of SNMP getnext commands using the ILMI interface to obtain the configuration information from the network device. If the network device sends a trap to the endpoint device indicating a change has been made to the configuration parameters stored in the network device for a PVC, a series of SNMP getrequest commands are made using the ILMI interface to retrieve the configuration information for that PVC from the network device. If the endpoint device detects an interruption in communication with the network device, the endpoint device discards the information retrieved previously.

Abstract: A method and apparatus for filtering a packet in a network is disclosed. The packet includes a packet header and packet data. The packet is intercepted. It is then determined if an access list exists for the packet, the access list including filtering criteria that dictates filtering of the packet in accordance with contents of the packet data. If no access list is determined to exist for the packet, the packet is forwarded. However, if an access list is determined to exist for the packet, the packet is filtered in accordance with the filtering criteria stored in the access list.

Abstract: A method of exchanging data streams between a local exchange and a number of access devices for serving a plurality of destination users, the method comprises the steps of: (a) providing a local exchange capable of generating at least one output data stream and of receiving at least one corresponding input data stream for carrying data blocks respectively relevant to one or more of the access devices; (b) providing two or more said access devices, each permitting passage there-through of at least one data stream carrying data blocks, being capable of extracting, from said at least one data stream, data blocks relevant to this particular device and of introducing there-into data blocks to be transmitted from this particular device to the local exchange; and (c) arranging one or more close loop data streams, each being intended for serving said two or more access devices using one of said output data streams and the corresponding input data stream of the local exchange, by causing the output data stream leaving

Abstract: There is disclosed a delay budget controller for use with a decoder buffer that receives streaming data packets over a data network from a streaming transmitter and stores the data packets in a plurality of access units for subsequent retrieval by a streaming data decoder. The delay budget controller comprises 1) a first controller for monitoring at least one network parameter associated with the data network; and 2) a second controller for monitoring in the decoder buffer a delay budget region comprising a sequence of access units that are about to be accessed sequentially by the data decoder. The delay budget region comprises a retransmission region and a late region separated by a temporal boundary, wherein the second controller detects missing data packets in the retransmission region and the late region and, in response to detection of a missing data packet in the retransmission region, transmits a retransmission request for the missing data packet to the streaming transmitter.

Abstract: A shared buffer packet switching device is provided for receiving data packets via associated ones of a plurality of receive ports, and for transmitting data packets via associated selected ones of a plurality of transmit port.

Abstract: A method and system for selecting an optimal size of a jitter buffer in a real time communications system includes calculating a frame loss rate from packet arrival statistics. The packet arrival statistics include determining an average queue time a frame spends in a jitter buffer and determining the difference between an expected arrival time and actual arrival time of a sample of data packets into a receiver. The frame loss rate is calculated by considering the frames that arrive late, frames that are lost in the network and frames that overflow due to an arriving burst of frames.

Abstract: A high-speed wavelength-division multiplexed (WDM) network that provides compliant, “invisible” paths of adaptive capacity from an external information source to an external information sink is described. The WDM network includes a plurality of high-speed electronic edge switch modules that are connected by WDM optical links to parallel-plane switch core modules. Smearing distributors ensure that packets to be transferred to a given output link are distributed evenly among the planes of the core modules. Consequently, contention is resolved. Each edge switch is connected to each core module by a WDM optical link. For purposes of admission control, the capacity of the link, rather than the capacity of channels in the link, is considered. This provides much improved granularity in connection bandwidth. The smallest connection may be a few kb/s, while the largest connection may be link capacity. Each edge switch is also adapted to accept data from external sources in a plurality of formats.

Abstract: A network switch, configured for performing layer 2 and layer 3 switching in an Ethernet (IEEE 802.3) network without blocking of incoming data packets, includes a network switch port having a filter (i.e., a packet classifier module) configured for evaluating an incoming data packet on an instantaneous basis. The filter performs simultaneous comparisons between the incoming data stream of the data packet and multiple templates configured for identifying respective data protocols. Each template is composed of a plurality of min terms, wherein each min term specifies a prescribed comparison operation within a selected data byte of the incoming data packet. The templates may be programmed by a user and stored in an internal min term memory. Moreover, the multiple simultaneous comparisons enable the network switch to perform layer 3 switching for 100 Mbps and gigabit networks without blocking in the network switch.

Abstract: A multi-port Ethernet device having a MUX mode passing internal status signals (e.g., ACT, LINK, SPEED, FDUP, CS, TPJS, TPAPS, RS, and/or XS) for each of a plurality of Ethernet ports in parallel over a common set of external pins. The Ethernet device may be ‘fixed’ in a multiplexed mode such that the MUX mode is the only way in which internal status signals for each Ethernet port is transmitted external to the Ethernet device, or the Ethernet device may provide a MUX mode for status signal output in addition to otherwise conventional output modes (e.g., a parallel status signal output mode and/or a serial status signal output mode). In MUX mode, all desired internal status signals (e.g., all nine (9) standard Ethernet status signals) are time division multiplexed onto the common set of external pins one Ethernet port at a time.

Abstract: An arbiter circuit is provided for resolving a plurality of N request signals received from a plurality of agents requesting access to a resource.

Abstract: According to the ITU recommendations for SDH or SONET, a payload exceeding the transmission capacity of the largest virtual container can be divided over several concatenated virtual containers. According to a method for the transmission of such a payload via a synchronous information transmission network (NET), the payload is divided into blocks and the individual blocks are packed into virtual containers (VC4), each of which has a path overhead and a payload field, and are transported as a virtual concatenation in at least one transport module. A pointer (Z) that points to the next virtual container in the concatenation is inserted in the path overhead of all virtual containers (VC4) except the last virtual container in the concatenation. This makes it possible to change the number of concatenated virtual containers (VC4) during a connection.

Abstract: A communications system and interface (109, 210) for interfacing a proprietary digital telephone (108, 114) to a local area network (LAN) (104). The interface may be embodied in a computer expansion card or a stand-alone unit. The interface converts signals from the proprietary digital telephone's communication protocol to the LAN's communication protocol. In a specific embodiment, the LAN communication protocol is the H.323 protocol.

Abstract: A system and method for improving the delivery of data between a first signal transmitter/receiver device and a second signal transmitter/receiver device. Data is dynamically sized into at least one data packet having a data packet size that is no greater than an operational maximum data packet size capable of being transferred between the first wireless signal transmitter/receiver device and the second wireless signal transmitter/receiver device. At least one data packet is transferred from the first signal transmitter/receiver device to the second signal transmitter/receiver device until all data has been delivered.

Abstract: A system and method for enabling an optical network unit (ONU) in a passive optical network to scramble data and send the scrambled data upstream to an optical line termination unit (OLT). In passive optical networks the clocks in the OLT and ONU are synchronized by recovering the clock from the data signal. However, the clocks may drift when no data transitions occur on a long string of data. In addition, the OLT may require data transitions to ensure proper adjusting of its receive threshold. In either circumstance, collectively called Loss of Synchronization, the data may not be received correctly by the receiver and the transmitter will need to resend the data. In the present invention, the transmitter will vary the seed used in the scrambling operation. The use of a different seed per each transmission significantly reduces the chances that a loss of synchronization will occur.

Abstract: A light source for an external cavity laser comprises a semiconductor laser 1 having a first facet to which is applied an antireflection coating 1A and a second facet to which is applied a increased reflection coating 1B defining a predetermined reflectivity, lenses 5, 6, a diffraction grating 2, and a mirror 3, wherein a light emitted from the first facet is converted into a parallel light by the lens 5, and the parallel light passes through the diffraction grating 2 to select a wavelength and is reflected to the diffraction grating 2 by the mirror 3 to select a wavelength via the diffraction grating 2 again, and the parallel light is converged by the lens 5 to be fed back to the semiconductor laser 1, and a light emitted from the second facets is converged by the lens 7 to be output to an optical fiber 4.

Abstract: A method of generating light pulses in an ultrawide band ranging from the near-infrared region to the near-ultraviolet region. Fundamental sub-picosecond pulses emitted from an ultrashort pulse laser (1) are passed through a nonlinear optical material (6) to produce wavelength-converted pulses whose center wavelength differs from that of the fundamental pulses. The method comprises the steps of separating the converted pulses from the fundamental pulses, delaying the converted pulses relative to the fundamental pulses, adjusting the polarization of the converted or fundamental pulses, adjusting the energy of the fundamental and converted pulses, superposing the separated fundamental and converted pulses on each other, and allowing the superimposed pulses to pass through a nonlinear optical material (22).

Abstract: A system for producing a green or UV output beam for illuminating a large area with relatively high beam fluence. A Nd:glass laser produces a near-infrared output by means of an oscillator that generates a high quality but low power output and then multi-pass through and amplification in a zig-zag slab amplifier and wavefront correction in a phase conjugator at the midway point of the multi-pass amplification. The green or UV output is generated by means of conversion crystals that follow final propagation through the zig-zag slab amplifier.

Abstract: A microcontroller-based controller executes interleaved DC bias and gain control routines using monitored values of the monitored photocurrent output signal of a Mach-Zehnder laser modulator to derive a gain setting for the modulation drive signal and a bias level setting for the DC bias level, without tuning or adjustment. Subsequent to convergence of the gain and bias level settings, the control unit may repetitively interrupt and restart the DC bias and gain control routine at intervals that are staggered in a random time fashion, to achieve spectral dispersion of the gain and bias level settings, and provide insensitivity to periodic environmental noise.

Abstract: The present invention is a device for avoiding sliding discharges in pre-ionization in a gas laser with corona discharge. The invention uses a pair of main electrodes provided in a closed gas discharge volume, and at least one pair of corona electrodes which are arranged in the immediate vicinity of the pair of main electrodes. The individual electrodes, which include a tube-like sheathing of dielectric material, are designed to be open on both ends and contain an electrically conducting rod, or core, introduced into the interior and projecting beyond the sheathing. The invention is distinguished by the provision that the material selection, the shaping of various elements associated with the gas discharge volume, or a combination of material selection and shaping is made in such a way that a specific capacitance per unit area is provided in the surface region on both ends of the sheathing is lower than the capacitance in the central region of the sheathing between its both ends.

Abstract: A light-emitting device driving circuit. The circuit uses an adaptive feedback control circuit to control the gain of a driving circuit and set the modulation current output of the driving circuit, so as to automatically adjust the differential gain stage to the optimal gain and obtain the optimal current output waveform under any operating condition, and further to eliminate overshoot and duty cycle distortion. The light-emitting device driving circuit includes a tunable gain-controlled differential amplifier; a first differential output stage and a negative feedback control circuit. The negative feedback control circuit further includes a detection circuit, a comparison circuit and a second differential output stage.

Abstract: In order to form a wavelength tunable laser capable of tuning a wave over a wide range by simple control means, a thin film heater is mounted either over an upper electrode of a ridge waveguide semiconductor laser having ridge waveguides on a semiconductor substrate or over the semiconductor substrate and on both sides of the ridge waveguide with a gap of a few &mgr;m. By controlling a current passed to the thin film heater, the oscillation wavelength of the semiconductor laser is tuned. In the case where the thin film heater is mounted over an upper electrode of a ridge waveguide, a nonconductor is formed on both sides of the ridge conductor to more efficiently enable heat from the heater to reach an active layer of the ridge waveguide more efficiently.

Abstract: In a semiconductor laser device, a semiconductor laser chip is placed on a stem so that an end surface of the semiconductor laser chip, on which the main radiation side light emission point is located, protrudes from an edge of a header portion of the stem or from an edge of a header portion of a sub-mount provided on the stem so as to conceal no light emission points of the semiconductor. A conductive die bonding paste is used for the die bonding of the semiconductor laser chip. A chamfered portion or a rounded corner portion is formed at the edge of the header portion of the stem or the edge of the header portion of the sub-mount provided on the stem. Also, an optical pickup is constructed of at least the semiconductor laser device, a diffraction grating, a photodetector, a condenser lens and an object lens.

Abstract: A high-output semiconductor laser element includes a plurality of laser structures which are superposed on a substrate one on another with a P+N+-tunnel junction intervening between each pair of the laser structures. Each of the laser structures includes at least one active layer interposed between a P-type clad layer and a N-type clad layer. The active region of each of the laser structures is not smaller than 10 &mgr;m and not larger than 80 &mgr;m in width. The distance h between the active layers which are most distant from each other in the active layers of the laser structures is not larger than the width W of the active region which is the widest in the laser structures. The width of said semiconductor laser element is not smaller than W+2h.

Abstract: A semiconductor laser diode array including a plurality of laser diode bars, each carried by a submount and forming a subassembly. Each subassembly is separated by a flexible or compliant electrically conductive spacer. All connections within the array are by way of a non-fluxed solder, that may be hard and/or soft, reflowed in a non-oxidizing atmosphere in a simple mechanical stack fixture to create nearly void-free solder joints with relatively high thermal integrity and electrical conductivity. Flexible electrically conductive spacers are disposed between the subassemblies to eliminate tensile stress on the laser diode bars while providing electrical conductivity between subassemblies. The subassemblies are carried by a thermally conductive dielectric substrate, allowing waste heat generated from the bars to be conducted to a cooling device. The invention eliminates known failure modes in interconnections, minimizing tensile strength on the diode arrays, and increasing the useful life of the array.

Abstract: A vertical cavity surface emitting laser (VCSEL) device includes a pair of diffusion Bragg reflectors (DBRs) sandwiching therebetween a multiple quantum well (MQW) comprising active layers. The bottom DBR includes a lower layer structure having AlAs layers having a higher thermal conductivity and AlGaAs layers in pair and an upper layer structure acting anti-oxidation layers and having a pair of AlGaAs layers having different Al contents. A selectively oxidized AlAs layer disposed as the top layer of the bottom DBR comprises an Al-oxidized area and a non-oxidized layer for confinement of current injection path.

Abstract: A gas discharge laser system for generating a laser beam, such as an excimer or molecular fluorine laser system, includes a laser resonator with an optical element for making wavefront corrections such as an adaptable optical element, a phase conjugating mirror, or a retroreflector array. The resonator preferably also has one or more line-narrowing optical elements for narrowing the bandwidth of the laser beam. One of the resonator reflectors or a transmissive or reflective intracavity optical element of the laser may include the adaptable optical element, phase conjugating mirror or retroreflector plate. A beam expander may be disposed before the adaptable optical element, phase conjugating mirror or retroreflector array for increasing the radius of curvature of the wavefront of the laser beam. A detection and control system including a processor and a detector may be used for controlling the contour of the wavefront correcting optical element in a feedback loop.

Abstract: An E-Diagnostic system for monitoring a state of an excimer laser or molecular fluorine laser system includes a processing device and an interface. The processing device runs a program for outputting parameter requests to the laser system, receiving parameter values from the laser system in response to the parameter requests, and storing the parameter values such that a record of the state of the excimer or molecular fluorine laser system is kept. The interface signal-couples the processing device with the laser system permitting the outputting of the parameter requests and the receiving of the parameter values between the processing device and the laser system.

Abstract: A method and apparatus for reducing processing requests of a pool of soft modems is disclosed. In one embodiment, a remote access concentrator comprises a memory, a processor, an interface bus, and a host interface. In one embodiment, the processor is coupled to the memory to operate a pool of soft modems in parallel with a common retrain handler, the common retrain handler includes a queue to store retrain requests, a request management block to retrieve the retrain requests and to identify modems that correspond to the retrain requests within a period of time, and a retrain engine to perform retrain procedures in accordance with modem standards.

Abstract: The furnace comprises a tubular inner chamber for the treatment of the raw material, mounted inside the enveloping body of the furnace which is insulated from the exterior and is provided with internal resistor systems for heating the chamber of the furnace by radiation, comprising means for feeding raw material at one end and means for controlling the output of completed product at the other end of the treatment chamber of the furnace, inside which a worm screw, driven in rotation from the exterior, is mounted rotatably, respective percussion devices being incorporated in the ends of the screw to prevent compaction of the mass on the screw.

Abstract: A method (50) of operating a communications receiver (20). The method receives a communications signal (10) which is transmitted via a channel, where the communications signal comprises received known pilot data (DP) and received information data (DI), the known pilot data and information data being sequentially transmitted. The method then estimates a first channel impulse response (52) for the channel, wherein the first channel impulse response is in response to the received pilot data. Next, the method determines (54) a group of estimated information data in response to the first channel impulse response. Next, the method estimates a second channel impulse response (56) for the channel in response to the estimated information data. Thereafter, the method forms (56) a combined channel impulse response for the channel, using differing weights as applied to the first and second channel impulse responses.

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 spread-spectrum communication apparatus includes an analog modulator and demodulator for modulating and demodulating information in its transmitter and receiver respectively. The apparatus also includes a spreader and de-spreader for modulating and demodulating a spread-spectrum signal respectively in its transmitter and receiver. This structure widens a dynamic range of the RSSI with an inexpensive and simple circuit. This structure also allows the apparatus to operate in a stable manner against an intense input signal, to detect an “out of sync” in a highly reliable manner and move immediately to a “sync-tracking mode”.

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: An apparatus and method for spread spectrum multiuser communication receivers is disclosed that includes, an adaptive filter adapted to minimize a block error function, wherein the filter tap weights are updated according to a non-linear optimization algorithm adapted for block processing of time-varying data.

Abstract: A spread spectrum data transmission apparatus, suitable for use in radiotelephony utilizing Code Division Multiple Access (CDMA), includes a receiver for receiving data organized in symbols having a duration Ts These symbols are spread by a spreading code having a period Tc prior to transmission over a transmission channel that has a plurality of main broadcasting paths, each broadcasting path producing a delay.

Abstract: Provided is an apparatus for detecting a correlation of samples with a spread code comprising: an L-chip accumulator which inputs the samples to generate and output an intermediate correlation signal of a bit width of W, wherein W is an integer larger than one; memories as many as M−1, each of which has a data width of 2W bits and addresses as many as L×N/2 and stores samples of the intermediate correlation signal as many as L×N while combining two samples as one pair; an adder which has input terminals as many as M and inputs from one of the input terminals the intermediate correlation signal which is outputted from the L-chip accumulator and from the other of the input terminals the intermediate correlation signal which is outputted from a corresponding memory among the memories; and a controller which supplies the intermediate correlation signal outputted from the L-chip accumulator to the memories as many as M−1 in rotation with a unit of L×N samples, and reads, and supplies

Abstract: A method for optimizing a bit-to-symbol mapping operation. The method has steps of (a) determining a most probable symbol selection error made during a space-time decoding operation; and (b) selecting a bits-to-symbol mapper such that a bit-to-symbol mapping step results in a most probable symbol selection error, made during a space-time decoding operation, causes a minimal number of bit errors. The bits-to-symbol mapping step can be carried out so as to minimize an average number of bit errors resulting from an occurrence of the most probable symbol selection error, as well as from an occurrence of at least a second most probable symbol selection error, during the space-time decoding operation. A space-time coded communications system that operates in accordance with the method is also disclosed.