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: An enhanced spread-spectrum uplink technique provides more efficient packet transfer in a wireless network. A mobile station requests to utilize an uplink channel, typically, a physical dedicated channel. If the network will grant access, a base station sends back a channel-request-granted message, which specifies a transmission start time and length. The base station starts related downlink transmissions at the start time, and at a time thereafter, the mobile station starts sending packet data over the uplink physical dedicated channel. After a transmission of no more that the specified length, the mobile station ceases its uplink transmission on the dedicated channel, and the base station and/or the mobile station can immediately release one or more channel resources. The grant message and/or the subsequent signaling communications from the base station may also specify a modulation scheme and a channelization code for the uplink channel.

Abstract: Techniques and apparatus for identifying the target mobile stations for data transmission in a wireless communication network.

Abstract: A method and a system are described for the transmission of data between one base station and several mobile stations via radio channels, the data streams each differing in terms of a code. In a modulator, a pre-equalization of the signals is performed in which the transmission properties of all the radio channels and the different codes of all the radio channels are taken into account.

Abstract: A method and system for the synchronization of the transmission of digitally converted analog modem signals between two or more modems using either RF over-the-air or A/C power line communication channels. This invention provides for modem speed optimization by minimizing or eliminating clock variance between the modems in a digital communication system. A fixed delay is created and maintained during modem operation. This invention is also adapted to function in a full-duplex communication system maintaining a fixed delay in both directions.

Abstract: A method of adaptive Walsh code allocation in a wireless communication system. The method includes the step of each voice user transmitting quality condition signal, such as a pilot signal strength measurement to a corresponding base station. Upon receiving each quality condition signal, the method includes determining a spreading factor for each voice user in response to its quality condition signal. A Walsh code is thereafter allocated to each voice user in response to the determined corresponding spreading factor. Thus, for example, if the quality condition signal of a first voice user is relatively higher than the quality condition signal of a second voice user, the spreading factor allocated to the first voice user should be longer than the spreading factor of the second voice user.

Abstract: An apparatus and method are disclosed for acquiring by a mobile terminal a pseudo-random noise (PN) sequence of a pilot signal received from a base station by means of a searcher, designating a phase of the acquired PN sequence as a reference phase to track the phase of the acquired PN sequence, and measuring an energy difference between an early path and a late path for the reference phase in a mobile communication system. In the apparatus and method, a first energy measurer measures a first energy value from a PN sequence with the reference phase, and a second energy measurer alternately measures energy values of the early path and the late path for the reference phase and outputs a second energy value.

Abstract: Control information, which is transmitted through a circuit different from the one used for the transmission of a plurality of pieces of information to be multiplexed, is analyzed. When the analysis results in a determined intra-TTI data length of information having longer Transmission Time Interval, it is determined whether a range of values that TFCI may take is limited or not. If the determination provides a positive result, the intra-TTI data length of information having a longest Transmission Time Interval which has been determined by the latest TFCI decoding is used as a base for limiting TFCI candidates to be decoded next, so as to decode the TFCI.

Abstract: This invention involves a two-level variable chip rate spreading and despreading method used in CDMA systems. The total spreading gain is the product of the two level spreading factors. Orthogonal sequences, ZCZ sequences and Pseudo-Noise (PN) sequences can be employed as the first- and second-level spreading codes. By employing the two-level spreading method, the interference existing in the systems can be suppressed efficiently and the system performance can be improved significantly.

Abstract: Various embodiments are described which may serve to improve spreading channel code selection in wireless technologies that employ two-stage ranging. For example, some of the embodiments enable a number of spreading codes to be reused at each network node (111, 112), potentially increasing the number of codes available to each remote unit and thereby reducing the collision rate. Rather than simply selecting a spreading channel code randomly, remote units (101-103), in some embodiments, select a spreading channel code based on one or more considerations such as pilot signal strength, remote unit location, a remote unit mobility level, and a priority class associated with the remote unit. Depending on the embodiment, network nodes can partition the spreading codes into groups and then assign link bandwidth to remote units based on the group associated with the code selected by that remote unit.

Abstract: A method and device for estimating a target chip index value in a code-division multiple access receiver. The receiver receives signals from a transmitter that uses a plurality of transmitted chips for data transmission through a plurality of multipath channels. As each channel is expressible as a channel impulse response at a given instant in time, the impulse response can be sampled and the samples indexed by a plurality of delay sample indices. The target chip index value can be determined based on the first moment of the delay sample indices over an impulse response.

Abstract: A system and method for the automatic establishment of a connection between a human interface device and a host transceiver unit, wherein the system includes a host transceiver unit configured to be connected with a host via a bus, and configured to wirelessly exchange data with a human interface device; a human interface device configured to wirelessly exchange data with a host transceiver; and a computer readable media having instructions thereon, wherein said instruction include routines for synchronizing the host transceiver unit and the human interface device for wirelessly exchanging data between the host transceiver unit and the human interface device at a spread spectrum modulation pattern which is determined by the host transceiver after the host transceiver unit and the human interface device have acknowledged each other's presence.

Abstract: This invention provides techniques for a CDMA system having high spectrum efficiency with low transmit power. Each transmitter comprises means of selecting some core-sequences out of multiple sequences to make them convey plural data, means of producing an enveloped selected sequence with such a method as to arrange as guard sequences to a repeated sequence made by repeating each of the selected core-sequences, means of modulating a user specific orthogonal carrier frequency by the enveloped selected sequence to produce a transmit-symbol, and means of transmitting the transmit-symbols. And a receiver comprises means of demodulating a receive-symbol with one of the user specific carrier frequencies to produce a base-band receive-symbol, means of separating respective components corresponding to the sequences selected by the user, by analyzing the base-band receive-symbol with a matrix composed of a channel response vector from the user to the receiver to detect plural data on the components.

Abstract: A method for communicating channel estimates on a plurality of subcarriers between a transmitting device and a receiving device. The transmitting device determines a channel estimates on a plurality of subcarriers and then encodes the channel estimates into at least one encoded channel waveform. Then the transmitting device transmits the at least one encoded channel waveform to the receiving device.

Abstract: Transmitting an ultra wideband (UWB) signal in some embodiments comprises reducing power within a first sub-band with respect to a nominal power of the UWB signal within the first sub-band and correspondingly increasing power within a second sub-band with respect to a nominal power of the UWB signal within the second sub-band. An ultra wideband (UWB) transmitter comprises an input interface configured to receive data, a modulator configured to modulate received data into symbols and a power shaping component coupled to the modulator, configured to shape power density spectrum of a UWB signal being transmitted.

Abstract: A paging indicator deciding method of a mobile communication terminal in which a threshold value for deciding a paging indicator is variably set according to a SNR of a pilot channel. If the SNR of the pilot channel is in a range that a false alarm rate (FAR) has a large value, the mobile terminal determines a threshold value so that it can have the greatest value in a range that a miss probability (MP) does not exceed the standard value. If the SNR of the pilot channel is not in the range that the SNR has the large value, the mobile terminal determines a threshold value to obtain the smallest MP in a range that the FAR is not further increased.

Abstract: The present invention provides a method and system for clock and carrier recovery in a direct sequence spread spectrum communication system. The process involves the receiver receiving a digital signal that has been transmitted by a remote transmitter. The method for joint clock and carrier recovery comprises the following steps. The received signal is down-converted and the signal is then converted to digital form. The signal is de-spread to obtain the phase of the signal constellation. The clock error at the receiver is then estimated from the phase error of the signal constellation by means of an optimal linear estimator. The discrete carrier frequency offset of the received signal is then estimated from the estimated clock error. The optimal linear estimator used here for estimating the clock error is also the maximum likelihood estimator.

Abstract: The present invention relates to a method and system for transmitting in a wireless communication system, a transmission signal divided into at least two signal parts by using transmission beams of at least two subarrays (SA1, SA2) of an antenna array. The transmission beam of at least one of the at least two subarrays (SA1, SA2) is at least in part controlled based on a feedback information received from the receiving means (20). Thus, several beams are generated using an antenna array with more than two antennas, wherein an open-loop diversity is used to split the transmission between the beams, and a closed-loop feedback-based diversity is used to optimize the beams, as well as possibly the division of power between the beams. Thereby, the amount of feedback can be controlled so as to achieve significant feedback gain in a multi-antenna transmission even with non-maximal amounts of feedback.

Abstract: A new modulation scheme in UWB communications is introduced. This modulation technique utilizes multiple orthogonal transmitted-reference pulses for UWB channelization. The proposed UWB receiver samples the second order statistical function at both zero and non-zero lags and matches the samples to stored second order statistical functions, thus sampling and matching the shape of second order statistical functions rather than just the shape of the received pulses.

Abstract: An apparatus and a method for symbol decoding of baseband data in a wireless communications network is disclosed, and specifically CCK subsymbol prediction and symbol demodulation that occurs at 5.5 Mbps or 11 Mbps. The apparatus is configured to demodulate or predict the data differently, depending on the modulation rate. If the data was modulated at 11 Mbps, the ?3 rotator is rotated through each of its possible phase values and symbol correlation takes four clock cycles to complete. If the data was modulated at 5.5 Mbps, ?3 is not rotated with a set value of 0 within the correlator architecture, thereby saving power and reducing symbol correlation and subsymbol prediction to a single cycle while in such transmission mode.

Abstract: A spread-spectrum, code-division-multiple-access (CDMA), system with a remote station (RS) communicating with a first base station (BS). The remote station receives the first BS-packet signal, and transmits a first RS-packet signal to the first base station. The first RS-packet signal is spread by a first RS-chip-sequence signal at a second frequency. The first base station receives the first RS-packet signal. The first base station stores and forwards the despread first RS-packet signal to a central office (CO). The remote station monitors control and packet transmission channels of other base stations in geographic proximity to the remote station. Each of the base stations transmit BS-packet signals. The remote station determines, based on signal metrics and available capacity, when to change from the first base station to the second base station. The second base station stores and then forwards the despread second RS-packet signal to the central office.

Abstract: A method of tuning a station is disclosed, wherein a first pilot signal is applied on a circuit of the station and the resulting output power of the signal circuit is subsequently detected. A second pilot signal is then applied to the circuit and the resulting output power of the circuit is detected. The offset of the circuit is then tuned based on information of the resulting output power detected for the first and second signals. A station that is adapted to implement the method may be tuned by the manufacturer thereof or later after having already been taken into use. The tuning may occur automatically as response to a predefined event.

Abstract: A code division multiplexing system for a link between components of a satellite communications system is disclosed where, using spread spectrum techniques, channel blocks are each spread by a pre-assigned orthogonal chip-coded waveform. The pre-assigned orthogonal chip-coded waveforms are each preferably chosen according to the origin and destination of the channel block. The channel blocks are each spread over an intermediate frequency and then upconverted such that their spreading bandwidth is equal, or approximately equal, to the allocated bandwidth of the particular link through which they will be transmitted. The channel blocks are spread so they each have the same, or approximately the same, center frequency as the allocated frequency spectrum of the link.

Abstract: An apparatus and method for adaptive broadcast transmission. A broadcast transmission can be received. Insufficiency of a broadcast channel quality can be determined. A negative acknowledgement signal can be sent on a common uplink channel in response to determining the broadcast channel quality is insufficient. The negative acknowledgement signal can be received on the common uplink channel at another location, the negative acknowledgement signal indicating broadcast channel quality is insufficient. The broadcast channel quality can be adjusted in response to receiving the negative acknowledgement signal.

Abstract: A distributed spread-spectrum network, comprising remote stations and nodes. One or more hub node(s) connect(s) to a central telephone office. A node's spread-spectrum transceiver communicates, using packets having spread-spectrum modulation, over radio waves, with the remote stations. Each packet has a source address and a destination address, and may have other information such as a header, start of message, end of message, flow-control information, forward error correction, and message data. A store-and-forward subsystem stores and forwards one or more packets to and from the remote station. The store-and-forward subsystem stores and forwards the one or more packets to and from another node. A flow-control subsystem controls the store-and-forward subsystem, to store each packet arriving at the spread-spectrum transceiver. The flow-control subsystem communicates traffic information between each of the nodes.

Abstract: Transmissions on the dedicated channel are encoded using a set of paramaters that are picked from a large selection of potential parameters. If the remote station does not know the particular set of parameters that were used by a base station, then the remote station would have to attempt to decode the transmission using every set of parameters, until the transmission is decoded correctly. This is an inefficient methodology. Hence, transmission format information is typically transmitted on a broadcast channel so that a remote station could receive the transmission format information. However, the broadcast channel has reliability problems. New methods and apparatus are presented to allow a base station to determine an overlapping set of Walsh code sequences that can be used to send the transmission format information on the dedicated channel, rather than a broadcast channel. Using the overlapping set allows the remote station to decode the information.

Abstract: A modified adaptive minimum mean square error (MMSE) receiver detects a spread spectrum signal, minimizing interference among multiple users. The receiver receives multiple pilot bits and corresponding data bits. A channel is estimated using at least one of the received pilot bits and, simultaneously, the data bits are detected based on the pilot bit and an inverse of a gain of the receiver. The spectrum signal may be spread in accordance with a wideband code division multiple access (W-CDMA) format, in which the pilot bits are modified to include a predetermined bit sequence of alternating ones and negative ones.

Abstract: The contents of a counter at a remote station is used to select a Walsh cover, which is used to cover the acknowledgment or negative acknowledgment bits sent on a new reverse acknowledgment channel (R-ACKCH). In the new reverse acknowledgment channel, the value of the acknowledgment bits for the broadcast transmissions is used to select the Walsh code sequence that covers the acknowledgment bit for the dedicated transmissions. When a base station receives an acknowledgment message from the remote station, the base station checks the Walsh cover of the message and extracts the embedded counter content. If the embedded counter content of the received acknowledgment or negative acknowledgment differs from the local counter value, the base station determines that a synchronization problem occurred, such that the remote station is not operating with the current transmission format information. Hence, the counter values act as the sequence identifiers of the Walsh masks.

Abstract: A system for short range communications includes a transmitter capable of transmitting a colored noise-like preamble. A receiver receives the colored noise-like preamble and the receiver includes an antenna with an antenna pattern. A direction of the antenna is controllable by the receiver. A signal processor is connected to and responsive to the receiver. The signal processor detects and estimates the strength of the colored noise-like preamble.

Abstract: A device for restoring data from signals transmitted through plural antenna includes a plurality of despreading units to restore pilot and data signals by means of pilot and data Walsh codes, a path controller to selectively activate the despreading units, an antenna-waiting signal generator to generate an antenna-waiting signal with the pilot signals output from the despreading units, an adder to sum the data signals output from the despreading units, and a controller to control the path controller and the adder in accordance with a transmission scheme of a base station. The invention provides one receiver system for a mobile terminal to be adaptable to various environments of transmission diversity with base stations, such as orthogonal transmission diversity (OTD), time-switched transmission diversity (TSTD), selection diversity (STD), or transmission antenna array (TXAA).

Abstract: A discrete multitone stacked-carrier spread spectrum communication method is based on frequency domain spreading including multiplication of a baseband signal by a set of superimposed, or stacked, complex sinusoid carrier waves. In a preferred embodiment, the spreading involves energizing the bins of a large Fast Fourier transform (FFT). This provides a considerable savings in computational complexity for moderate output FFT sizes. Point-to-multipoint and multipoint-to-multipoint (nodeless) network topologies are possible. A code-nulling method is included for interference cancellation and enhanced signal separation by exploiting the spectral diversity of the various sources. The basic method may be extended to include multielement antenna array nulling methods for interference cancellation and enhanced signal separation using spatial separation. Such methods permit directive and retrodirective transmission systems that adapt or can be adapted to the radio environment.

Abstract: A code division multiple access (CDMA) communication system using spread spectrum signaling over a communication bandwidth uses two different signal spectra generated using two different respective spreading code formats, such as NRZ code formatting and Manchester code formatting, for respectively providing nonsplit spectra having a center peak and split spectra having a center null. The spectra are combined during transmission as a CDMA communication signal having a composite spectrum. The use of different code formats produces the composite spectrum of respective center peak and center null spectra that enables increased channel capacity.

Abstract: Method for transmitting a word representative of transmission parameters respectively allocated to the mobile stations in communication with a base station of a mobile telecommunication system, wherein it includes the step of: including, in each transmission burst a mid amble resulting from the sum of selected midambles among all the available midambles, said selection being done by said base station in relation with a word so that a selected mid amble corresponds to a binary element of said word equal to a first value and a non-selected mid amble corresponds to a binary element of said word equal to a second value, and considering a word the elements of which are in one-to-one relationship with the temporal positions of the estimations respectively corresponding to said available midambles.

Abstract: In a code division multiple access communication system (100), a method and an accompanying apparatus provide for an efficient control of a gain level of a communication channel at various mobility levels. A rate of change of a carrier to interference ratio (C/I) of a communication channel received at a receiver (400) is determined. The gain level of the communication channel may be based on the rate of change of the C/I of the communication channel. A mobility level of the communication channel may be compared to a low mobility threshold corresponding to a low mobility level. If the mobility level meets the low mobility threshold, the gain level of the communication channel may be based on the rate of change of the C/I of the communication channel.

Abstract: A signal that has been received over a first channel is estimated. A set of channels that the signal will be received over is determined. Based on the estimated signal and the set of channels, the signal is removed from a plurality of signals received over a second channel.

Abstract: A high data transmitter and a high data receiver that uses both Walsh codes and quasi orthogonal functions in spreading and despreading transmitted and received signals.

Abstract: In an environment where the transmission medium leading to the receiver is time-variant within a block of received signals, and where transmission medium has an finite impulse response extending over a number of symbols intervals, a receiver that includes a filter that, based on an estimate of the transmission channel, is controlled to have filter coefficients that minimize inter-carrier interference due to the intra-block time variations in the transmission medium. The estimate channel coefficients are determined from pilot signals and an interpolation process. When the receiver is an OFDM receiver, the pilot signals are advantageously selected to be in clusters that are equally spaced from each other in the time or the frequency domains. This approach applies to multiple antenna, as well as to single antenna arrangements, and to arrangements that do, or do not use space-time coding.

Abstract: A CDMA receiving apparatus includes a receiving section, a memory circuit, an estimating circuit and a generating circuit. The receiving section generates a baseband signal from a received radio signal, searches a path having the highest correlation with the received radio signal, generates a path delay quantity for the searched path and generates a demodulated signal as an object signal from the baseband signal based on the path delay quantity. The memory circuit stores at least one SIR value as a previous SIR value. The estimating circuit estimates the SIR value from the object signal and stores the estimated SIR value in the memory circuit. The generating circuit generates a TPC (transmission power control) bit signal for controlling transmission power from the estimated SIR value and the previous SIR value stored in the memory circuit based on the path delay quantity and a reference SIR value.

Abstract: Spread Spectrum baseband signals, in-phase and quadrature-phase cross-correlated baseband signals and other filtered baseband signals connected to modulators for providing modulated signals. Modulator selection for modulated signal selection or for multiple modulated signals provided to one or more antennas for signal transmission.

Abstract: A discrete multitone stacked-carrier spread spectrum communication method is based on frequency domain spreading including multiplication of a baseband signal by a set of superimposed, or stacked, complex sinusoid carrier waves. In a preferred embodiment, the spreading involves energizing the bins of a large Fast Fourier transform (FFT). This provides a considerable savings in computational complexity for moderate output FFT sizes. Point-to-multipoint and multipoint-to-multipoint (nodeless) network topologies are possible. A code-nulling method is included for interference cancellation and enhanced signal separation by exploiting the spectral diversity of the various sources. The basic method may be extended to include multielement antenna array nulling methods for interference cancellation and enhanced signal separation using spatial separation. Such methods permit directive and retrodirective transmission systems that adapt or can be adapted to the radio environment.

Abstract: A method and an apparatus for selecting an antenna from an antenna diversity array in a wireless communication system are provided. The method includes the steps of modulating an incoming signal with a spread-spectrum type modulation, measuring a signal quality value for each antenna in the antenna diversity array, and selecting an antenna from the antenna diversity array on the basis of the measured signal quality values. The step of measuring a signal quality value for each antenna may include computing peak-to-average ratio values by dividing a peak sample value by an average sample value, where the average sample value is determined by averaging all of the predetermined number of sample values for each of the plurality of incoming spreading codewords, and the peak sample value is determined by selecting the maximum of all of the predetermined number of sample values for each of the plurality of incoming spreading codewords.

Abstract: A spread spectrum noise shaper uses a modulation technique to achieve a greater signal-to-noise or signal-to-interference ratio (SNR or SIR). The technique doubles the system SIR, in principle. This doubling yields a doubling in system capacity. SNR is increased by receiving the spread spectrum signal in the presence of less noise near the edge of the spread spectrum bandwidth. The technique requires only small additions to a conventional spread spectrum system, in the form of an extra modulator at the transmitter, and an extra demodulator and filter at the receiver.

Abstract: The use of cyclic prefixes with OFDM transmissions is known. Typically the prefix length is chosen to be at least as long as the duration of significant multipath in the transmission channel. However, OFDM has disadvantages in terms of DSP load and transmitter power amplifier specifications. The use of a cyclic prefix with periodic CDMA codes has been found to yield equivalent performance in terms of orthogonality in a dispersive channel and yet overcomes the disadvantages of cyclicly prefixed OFDM transmissions. Examples are given of Walsh Hadamard binary periodic codes.

Abstract: A system (100), receiver (160-190) and method of operation for spread OFDM wireless communication (single user OFDM-CDMA with cyclic-prefix) by: equalizing the received spread OFDM signal (y) and splitting it into first and second portions (?1, ?2); making a decision on the second portion and subtracting the second portion from the received signal to produce a first difference signal; processing the first difference signal to recover the first portion of the received signal in which symbol interfering terms of the second portion are substantially reduced; making a decision on the first portion and subtracting the first portion from the received signal to produce a second difference signal; and processing the second difference signal to recover the second portion of the received signal in which symbol interfering terms of the first portion are substantially reduced. The process may be iterated extensively at this stage.

Abstract: A hybrid DSMA-CR/CDMA methodology provides efficient access to one of a group of packet channels in a spread spectrum wireless communication network. The base station broadcasts status information as to the availability and/or available data rates for each packet channel or group of channels. Each mobile station uses the status information to select an available channel and/or a channel with sufficient data rate. The mobile station then starts transmission of a series of access preambles, each of which contains a signature corresponding to the selected channel. The mobile station transmits the preambles at increasing power levels. When the base station detects a preamble transmission, the base station responds with a corresponding acknowledgement essentially permitting the mobile station to send its packet data along with any closed-loop power control information over the selected channel.

Abstract: A code-division-multiple-access (CDMA) system employing spread-spectrum modulation. The CDMA system has a base station (BS), and a plurality of subscriber units (SUs). The signals transmitted between the BS and SU use spread-spectrum modulation. The apparatus for maintaining control of power from an SU to a BS, comprises sending from the SU, using spread-spectrum modulation, a SU-spreading code, and detecting at the base station, the SU-spreading code from the SU. In response to detecting the SU-spreading code at the BS, a BS-spreading code is sent to the SU, using spread-spectrum modulation. At the SU, if the BS-spreading code is detected, then transmit power of the SU is reduced. If the BS-spreading code is not detected at the SU, then transmit power of the SU is increased.

Abstract: A communication system includes a mobile terminal and a base station. The mobile terminal estimates signal quality of a forward link during a first power control group period and determines a power control bit based on the estimated signal quality. The mobile terminal further transmits the power control bit on a reverse link during the first power control group period. The base station receives the power control bit on the reverse link and modifies forward link power based on the power control bit at commencement of a second power control group period.

Abstract: A system and method for transmitting a plurality of spread-spectrum signals over a communications channel having fading. The plurality of spread-spectrum signals are radiated by a plurality of antennas, with each antenna preferably spaced by one-quarter wavelength. A plurality of receiver antennas receive the plurality of spread-spectrum signals and a plurality of fading spread-spectrum signals. Each receiver antenna is coupled to a plurality of matched filters having a respective plurality of impulse responses matched to the chip-sequence signals of the plurality of spread-spectrum signals. A RAKE and space-diversity combiner combines, for each respective chip-sequence signal, a respective plurality of detected spread-spectrum signals and a respective multiplicity of detected-multipath-spread-spectrum signals, to generate a plurality of combined signals. The symbol amplitudes can be measured and erasure decoding employed to improve performance.

Abstract: A Walsh code assigning apparatus includes a retaining unit retaining assignment order information about an order of assignment of the plural Walsh codes such that one Walsh code having a smaller bit length becomes unable to he orthogonally separated as being precedent over another Walsh code having a larger bit length and a controller including a retrieving unit retrieving an idle Walsh code having an assignment request bit length in accordance with the assignment order information retained in the retaining unit, and assigning unit assigning the idle Walsh code, which has been obtained by the retrieving unit, to the spreading code of a last-named communication channel for which the assignment request is issued.

Abstract: A method is disclosed for operating a synchronous space division multiple access, code division multiple access communications system. The method includes steps of, within a coverage area of a base station (BS), (a) assigning the same spreading code to a plurality of subscriber stations (SSs); and (b) beamforming using an antenna array at the BS so as to maximize the signal to interference plus noise ratio for a signal transmitted from a desired SS, The beamforming operates to steer a null towards another same-code SS to minimize interference from the same-code SS. Assuming that the antenna array has M-elements (M>1), then individual ones of P orthogonal spreading codes can be reused ?M times within the coverage area, where 1/M<??1. The step of beamforming includes an initial step of despreading the signal received from the desired SS, followed by a step of spatial filtering.

Abstract: A pressurizing cap which may be readily attached and detached from the discharge neck of a bottle of carbonated liquid includes a housing having a first chamber proximate one end thereof and a skirt portion at an opposite end thereof which engages the bottle's neck. The first chamber retains a pressurized canister of innoxious gas such as carbon dioxide. The housing also comprises a second chamber. A first conduit leads from the first chamber to the second chamber, and a second conduit leads from the second chamber to the neck portion of the bottle. Means are provided within the second chamber for selectively connecting the first and second conduits whereby gas is released into the bottle. Liquid discharge means may also be provided which comprises a nozzle extending from the housing and a tube coupled at one end thereof to the nozzle and having an opposite end in communication with the liquid in the bottle. The cap is collinearaly mounted with the neck of the bottle.