Abstract: A method for generating a codebook to encode embedded information is described. A distribution pattern of symbols is determined. A first number of codewords associated with the distribution pattern of symbols is determined. A subset of codewords from the first number of codewords is selected. The subset of codewords is included in the codebook if the subset of codewords satisfies predetermined performance criteria.

Abstract: A wireless communication apparatus capable of minimizing the degradation in separation characteristic of a code multiplexed response signal. In this apparatus, a control part (209) controls both a AC sequence to be used in a primary spreading in a spreading part (214) and a Walsh sequence to be used in a secondary spreading in a spreading part (217) so as to allow a very small circular shift interval of the ZC sequence to absorb the interference components remaining in the response signal; the spreading part (214) uses the ZC sequence set by the control part (209) to primary spread the response signal; and the spreading part (217) uses the Walsh sequence set by the control part (209) to secondary spread the response signal to which CP has been added.

Abstract: A method includes encoding data according to a space time transmit diversity scheme and spatial-multiplexing the encoded data.

Abstract: A method for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses at least one channel, includes the steps of: a) encoding the source data to generate at least one data part and a control part; b) generating at least one spreading code to be allocated to the channel, wherein each spreading code is selected on the basis of a data rate of the data part and the control part and spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on same point or symmetrical with respect to a zero point on a phase domain; and c) spreading the control part and the data part by using the spreading code, to thereby generate the channel-modulated signal.

Abstract: A method for rate-shaping media streams; the method includes: receiving multiple input media streams, transmission parameters, wired transmission limitations and wireless transmission limitations that represent a current status of a wireless medium; and rate-shaping at least one input media stream out of the multiple input media streams, in response to: (i) the transmission parameters, (ii) the wireless transmission limitations, and (iiii) input media stream parameters. A system for processing media streams; the system includes: a controller, adapted to determine rate-shaping parameters in response to: (i) the transmission parameters, (ii) the wireless transmission limitations, and (iii) input media stream parameters; and a rate-shaper, connected to the processor, adapted to receive multiple input media streams and perform rate-shaping according to the rate-shaping parameters.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided in which a first pre-coding matrix for use on a portion of a set of resource blocks (RBs) is determined. At least one beamforming vector of the set of beamforming vectors is modified by applying a phase rotation to generate a modified pre-coding matrix. The modified pre-coding matrix is applied to one or more demodulation reference signals and data associated with the portion of the set of RBs for transmission using at least one antenna.

Abstract: The present invention relates generally to methods for generating a dynamic pilot symbol structure in spread spectrum communication systems, and in particular to the use of pilot symbols by user equipment in channel estimation. In one form, the method includes, allocating basic pilot symbols at the beginning of each data chunk and spread over the plurality of sub-carrier frequencies; and selectively replacing data symbols in each data chunk with adaptive pilot symbols according to the speed of the user equipment.

Abstract: A method and apparatus for utilizing code division multiple access in modulated reflectance transmissions comprises the steps of generating a phase-modulated reflectance data bit stream; modifying the modulated reflectance data bit stream; providing the modified modulated reflectance data bit stream to a switch that connects an antenna to an infinite impedance in the event a “+1” is to be sent, or connects the antenna to ground in the event a “0” or a “?1” is to be sent.

Abstract: There is an apparatus and technique for generating a sequence of modulated waveforms of finite duration in which the difference in start time of each waveform is shorter than the waveform's overall duration and each waveform in the sequence has independent data modulation imparted upon it. The apparatus consists of a bank of memory cells arranged in an N×M configuration with associated control circuitry, along with an arrangement scheme for the data in the N×M memory cells such that the waveforms will be correctly reproduced when the memory cells are addressed by the control circuitry in the prescribed order.

Abstract: The present invention provides a new and unique method and apparatus for a new data speed switching scheme for a wired data interface. The method features receiving high-speed serial data over a physical link using a first coding scheme in a receiver; receiving a transmission mode change signal transmitted with sequential information about a change in a data transmission mode of the receiver using a second coding scheme and switching the data transmission mode of the receiver in response thereto. The data transmission modes may include at least one low-power mode where no data transmission is possible and the receiver is powered down. The at least one low-power mode may include two different power down states, each having different wake-up times. The data transmission modes may also include at least one high speed mode where data transmission is possible and the receiver is on. The at least one high speed mode may include several high speed modes, each having different data transmission rates.

Abstract: A method for transmitting a plurality of sequences across a plurality of bands of a wireless spectrum is described in which a first sequence is produced using a set of reference signal sequences, wherein the set of reference signal sequences comprises at least CAZAC sequences and near-CAZAC sequences. A second sequence is also produced. The first sequence is transmitted in a first band of the wireless spectrum, and the second sequence is transmitted in a second band of the wireless spectrum. The first and the second sequences are transmitted concurrently by a same user equipment.

Abstract: Precoding a plurality of subcarriers in preparation for MIMO transmission is carried out by deriving preceding matrices from available information. When the number of data streams borne by the subcarriers equates to the number of transmit antennas employed in the MIMO transmission, the method comprises deriving, from respective acquired unitary precoder matrices for two of said subcarriers, interpolated precoder matrices for data streams intermediate the two subcarriers. The acquired and interpolated precoder matrices are then applied, as the case may be, at the respective subcarriers.

Abstract: In a wireless communication system wherein communication devices exchange information utilizing data units that conform to a first format, wherein the first format includes a short training field (STF) spread with a first spread code and a first cover code, a method is for generating a physical layer (PHY) data unit that conforms to a second format, wherein the PHY data unit is for transmitting PHY information. A first portion of the PHY data unit is generated to indicate the PHY data unit conforms to the second format, wherein the first portion of the PHY data unit includes an STF spread with at least one of a second spread code different than the first spread code or a second cover code different than the first cover code. A second portion of the PHY data unit is generated according to the second format, wherein the second portion of the PHY data unit includes PHY information elements not specified by the first format.

Abstract: Provided are a beamforming receiving/transmitting function and a beamforming receiving/transmitting structure, which are optimized for a given basic system in order to provide advanced performance in consideration of a wireless mobile communication system through a ultra-high performance CDMA array antenna based on continuously orthogonal spreading codes and a pre-rake scheme for non-interference communication. Also, there is provided a chip-level/symbol-level beamforming receiving/transmitting apparatus based on a multiple-input multiple-output (MIMO) system on a forward/backward link in order to be applied to various advanced wireless mobile communication applications by improving the performance and capacity of a Code Division Multiple Access (CDMA) array antenna system based on continuously orthogonal spreading codes and a pre-rake scheme for non-interference communication, and a forward and backward link automatic beamforming method.

Abstract: To improve the reliability of channel estimation, data symbols at determined positions of the transmitted data stream are replaced by quasi-pilot symbols. The quasi-pilot symbols carry data modulated onto the carrier with a different modulation scheme than the original symbols. The modulation scheme for the quasi-pilot symbols has a lower amplitude and/or phase ambiguity than the modulation scheme for the original data symbol.

Abstract: A dual burst transmitter for ultra-wideband (UWB) communication systems generates a pair of precisely spaced RF bursts from a single trigger event. An input trigger pulse produces two oscillator trigger pulses, an initial pulse and a delayed pulse, in a dual trigger generator. The two oscillator trigger pulses drive a gated RF burst (power output) oscillator. A bias driver circuit gates the RF output oscillator on and off and sets the RF burst packet width. The bias driver also level shifts the drive signal to the level that is required for the RF output device.

Abstract: By assigning a plurality of subcarriers 31 to a data channel 33 and assigning fewer subcarriers 32 than the plurality of subcarriers 31 to a control channel 34 and, in addition, locating the control channel 34 at the center frequency fc of a frequency band used to transmit the data channel 33, on the radio receiving apparatus side, the frequencies of a local signal by which the received signal is multiplied share the same value, thereby speeding up the switching between the control channel and the data channel.

Abstract: In some embodiments of the invention, OFDM symbols are transmitted as a plurality of clusters. A cluster includes a plurality of OFDM sub-carriers in frequency, over a plurality of OFDM symbol durations in time. Each cluster includes data as well as pilot information as a reference signal for channel estimation. In some embodiments, a plurality of clusters collectively occupy the available sub-carrier set in the frequency domain that is used for transmission. In some embodiments of the invention data and/or pilots are spread within each cluster using code division multiplexing (CDM). In some embodiments pilots and data are separated by distributing data on a particular number of the plurality of OFDM symbol durations and pilots on a remainder of the OFDM symbol durations. CDM spreading can be performed in time and/or frequency directions.

Abstract: A modulator for a communications system includes a spread spectrum coder and a pulse code modulator having a signal input port connectable to a signal output port of the spread spectrum coder. The modulator performs a robust and error free modulation and coding scheme by using a modified spread spectrum scheme combined with pulse code modulation. The communication system contains a low data rate, noise robust modulation and coding scheme using a very simple transmitter. This results in a very straightforward transmitter circuit, reducing size and costs of the transmitter.

Abstract: A delta quantizer for MIMO pre-coders with finite rate channel state information feedback may comprise partly quantizing a change in channel state information in a MIMO pre-coding system onto at least a first and a second codebook, each of which comprises one or more unitary matrices, using a cost function; and generating the at least first and second codebook based on at least the channel state information. The channel state information may be a matrix V and the cost function may be defined by the following relationship: f ? ( A ) = ( 1 N ? ? j = 1 N ? ? a jj ? 2 ) where A is a matrix of size N by N and aij is element (i,j) of matrix A. One or more unitary matrices may be generated for the at least first codebook from at least a first set of matrices and a second set of matrices.

Abstract: A method and apparatus are disclosed for modulating a communication signal in a code division multiple access (CDMA) environment using orthogonal N by N Hadamard spread spectrum codes Orthogonal spreading codes are used that have lengths that are not a power-of 2 to provide additional channel variability for various multimedia applications and increase the flexibility of the number of channels/bandwidth relationship. The Hadamard codes are multiples of 4 (4n) and demonstrate a good cross-correlation property, making them very useful in the flexible design of code division multiple access (CDMA) systems. A transmitter encodes each of N data streams (N not being a power of 2), to be transmitted using a 4n codeword, Ni. The received signal is passed through a filter matched to the characteristics of the appropriate codeword, Ni, and PN spreading sequence.

Abstract: A transmission method for transmitting modulation signals of a plurality of channels to the same frequency band from a plurality of antennas. At the time when a symbol used for demodulation is inserted in a channel, in another channel symbol, the same phase and quadrature signals in the in-phase-quadrature plane are made to be zero signals. Thus, a plurality of modulation signals are multiplexed and transmitted and the transmitted multiplexed modulation signals are demultiplexed and demodulated at a reception apparatus, thereby improving the data transmission rate.

Abstract: A feedback signal is received from a feedback communication device. The feedback signal provides feedback information for a signal at a feedback rate. A modifying communication device modifies the signal by adjusting a nominal value of a transmit diversity parameter in accordance with the feedback information at a nominal value adjustment rate. The signal is perturbed according to the adjusted nominal value at a perturbation rate.

Abstract: The invention relates to an electronic device that includes a plurality of buffers and a phase locked loop. For each buffer a fractional divider is provided which is coupled to receive the output from the phase locked loop and configured to feed a divided output signal to a respective buffer. A spread spectrum clock control logic stage in the spread spectrum clock (SSC) is provided which is configured to individually adjust a value of the division of each fractional divider in order to individually and independently modulate the output signal of each fractional divider according to a spread spectrum modulation scheme.

Abstract: A digital subscriber line (DSL) modem that has a canceller digital filter for cancelling crosstalk and RF interference in a received DSL signal is disclosed. The modem includes common-mode sense circuitry and also differential-mode sense circuitry. Samples of the common-mode signal are acquired during a “quiet” period of initialization of the DSL modem, and samples of the differential-mode signal are acquired during live transmission of a DSL signal. An estimate of an autocorrelation function is obtained from the common-mode samples, and a cross-correlation of the common-mode samples and differential-mode samples is also estimated. Digital filter coefficients are derived from these estimates, based on the assumption that the common-mode samples acquired during the “quiet” phase represent crosstalk and RF interference present during differential-mode communications.

Abstract: A wireless communication system. The system comprises transmitter circuitry (BST1), the transmitter circuitry comprising encoder circuitry (50) for transmitting a plurality of frames (FR). Each of the plurality of frames comprises a primary synchronization code (PCS) and a secondary synchronization code (SSC). The encoder circuitry comprises of circuitry (501) for providing the primary synchronization code in response to a first sequence (32). The encoder circuitry further comprises circuitry (502) for providing the secondary synchronization code in response to a second sequence (54) and a third sequence (56). The second sequence is selected from a plurality of sequences. Each of the plurality of sequences is orthogonal with respect to all other sequences in the plurality of sequences. The third sequence comprises a subset of bits from the first sequence.

Abstract: A method for establishing a cyclic shift sequence to provide against the frequency offset is disclosed. The method calculates a distance between a channel response position of the sequence and an alias channel response position caused by a frequency offset, calculates the number of cyclic shifts per group according to the calculated distance, and establishes the cyclic shift (CS)-applying interval. This method easily establishes a cyclic shift (CS) interval at a specific location having no overlapping by considering a channel response of a reception (Rx) sequence and an alias location of this reception (Rx) sequence, although a reception (Rx) signal is shifted by a channel delay spreading or a propagation delay irrespective of categories of a domain generating a sequence, so that it can greatly reduce the number of the detection errors and the false alarm rate.

Abstract: A wireless communication apparatus wherein the performance can be prevented from degrading due to the affection of a frequency offset, while the sequence length of Zadoff-Chu sequence (ZC sequence) being kept long. In this wireless communication apparatus, a ZC sequence generating part (11) generates a ZC sequence corresponding to a preamble number that is selected at random and then inputted; a randomizing part (12) randomizes the ZC sequence; a preamble generating part (13) generates a preamble from the randomized ZC sequence; and a radio transmitting part (14) transmits, via an antenna (15), the preamble after subjecting it to predetermined radio transmission processes, such as a D/A conversion, an up-conversion and so on. For example, the randomizing part (12) multiplies the ZC sequence by a PN sequence so as to randomize the ZC sequence.

Abstract: A communications device, such as a GNSS receiver comprises an oscillator, having a temperature-dependent frequency characteristic, for generating signals at a nominal frequency; receiver circuitry, for receiving transmitted wireless signals using the signals generated by the oscillator; at least one temperature sensor, having a known positional relationship to the oscillator; an estimation device, for estimating a frequency of the signals generated by the oscillator, based on a measurement from the temperature sensor, and based on the temperature-dependent frequency characteristic of the oscillator; and at least one heat source. A change in the temperature of the oscillator is predicted, based on a state of the heat source, and further based on a model of the thermal properties of the communications device, and hence a change in the frequency of the signals generated by the oscillator is predicted, based on the temperature-dependent frequency characteristic of the oscillator.

Abstract: A pulse generator circuit is provided. The pulse generator circuit has an input adapted to receive an input electrical quantity and an output at which an output electrical quantity is made available. A transfer characteristic establishes a relationship between said input and said output electrical quantities. The pulse generator circuit is adapted to provide said output electrical quantity in the form of pulses having a predetermined shape, suitable to be used for UWB transmission. The transfer characteristic has substantially a same shape as that of said pulses. Moreover, a UWB modulating system exploiting the novel pulse generator is proposed.

Abstract: The present invention relates to a method for improving synchronization and information transmission in a communication system, including: generating a signal with a time symmetric property based on a uniquely identifiable sequence c(l) from a set of sequences, sending the signal over a communication channel, receiving the signal, calculating and storing a correlation, finding the delay that result in a maximum correlation magnitude, detecting the unique sequence c(l) from the set of sequences. The method is distinguished by: generating the signal with a centrally symmetric part, s(k), the centrally symmetric part s(k) being symmetric in the shape of the absolute value thereof, storing the reverse differential correlation D(p) from a block of N received signal samples r(k), k=0, 1, . . . , N?1. The present invention also relates to a transmitter unit and a receiver unit of a communication system, and a radio communication system.

Abstract: Closed loop multiple-antenna wireless communications system with antenna weights determined by maximizing a composite channel signal-to-interference-plus-noise ratio minimum. Multiplexed symbol streams over subsets of antennas enhance throughout.

Abstract: Systems and methods for adjustable transmit diversity (adjustable PSTD) are provided. A base station transmits information to a mobile station over two antennas. Using information received from the mobile station related to channel conditions, the base station can adjust a frequency offset between the information transmitted over the two antennas.

Abstract: A closed-loop signalling method controls multiple transmit beams. The method also includes transmitting a plurality of beams from a first transceiver via a plurality of transmission channels to a second transceiver, evaluating, at the second transceiver, characteristics of the plurality of transmitted beams received at the second transceiver. The method also includes deriving, at the second transceiver, beamforming information for being fed back from the second transceiver to the first transceiver based on the evaluated characteristics. The beamforming information is usable for controlling, at the first transceiver, the transmitting of the plurality of beams. The method also includes selecting, at the second transceiver, at least one set of beamforming information for being fed back from the second transceiver via a feedback path to the first transceiver.

Abstract: A system and method for encoding data for transmission over a telecommunications network. The system and method involve embedding a control data block (Ik0) within a plurality of real data blocks (IN0). Preferably, real data in the real data blocks (INO) is convoluted with at least some of the control data in the control data block (Ik0) For example, each entry in each real data block (INO) may be phase convoluted with phase angle of the corresponding entry in the control block using an encoding module. Once this is done, the real data in the real data blocks and additionally the control data block in the control block is modulated with every sub carrier.

Abstract: Multiple transmit antenna transmission together with preferably pseudo-random, antenna-specific, scrambling (PRAS) is utilized to scramble incoming data differently on different antennas for those users requiring frequency diversity type transmissions. When PRAS is activated for a particular allocation, each transmit antenna applies a different scrambling sequence to the data symbols that are transmitted in the allocation.

Abstract: A surface acoustic wave (SAW) expander based transmitter and correlator based receiver comprises SAW devices that perform expander or correlator functions based on the types of signals inputted to the SAW devices. The SAW devices incorporate chirp with adaptive interference and programmable coding capabilities. The SAW devices and method of operating the devices allow the implementation of very low power radios that overcome problems with temperature drift, lithography constraints and interference and jamming suffered by prior art implementations.

Abstract: Provided is a radio communication device which can suppress inter-code interference between an ACK/NACK signal and a CQI signal which are code-multiplexed. In this device, a diffusion unit (214) diffuses the ACK/NACK signal inputted from a judgment unit (208) by using a ZC sequence. A diffusion unit (219) diffuses the CQI signal by using a cyclic shift ZC sequence. By using a Walsh sequence, a diffusion unit (216) further diffuses the ACK/NACK signal which has been diffused by using the ZC sequence. A control unit (209) controls the diffusion unit (214), the diffusion unit (216), and the diffusion unit (219) so that the minimum value of the difference between the CQI signals from a plurality of mobile stations and a cyclic shift amount of the ACK/NACK signal is not smaller than the minimum value of the difference between the cyclic shift amounts of the ACK/NACK signals from the plurality of mobile stations.

Abstract: Techniques for introducing information into a data stream first obtains the spectral values of the short-term spectrum of the audio signal. Separately, information to be introduced are combined with a spread sequence obtaining a spread information signal, whereupon a spectral representation of the spread information is generated, then weighted with an established psychoacoustic maskable noise energy to generate a weighted information signal, wherein energy of the introduced information is substantially equal to or below the psychoacoustic masking threshold. The weighted information signal and the spectral values of the short-term spectrum of the audio signal are then summed and afterwards processed again to obtain a processed data stream including audio information and information to be introduced.

Abstract: A control unit generates packet signals to be transmitted. The control unit uses either a first packet format, where a second known signal defined by a second radio communication system different from a first radio communication system is assigned anterior to a first known signal defined by the first radio communication system, or a second packet format, where the first known signal is assigned in an anterior part. Subcarriers to be used in the first known signal contain subcarriers to be used in the second known signal, and the first known signal and the second known signal are defined by different values.

Abstract: Methods and apparatuses for chaotic communication in a wireless personal area network, A chaotic information carrier is generated for a first predetermined frequency range using a ring-structure oscillator. The ring structure oscillator includes a non-linear element. Chaotic pulses are generated by modulating the chaotic information carrier for the first predetermined frequency range with a data signal. A shape of a spectral density envelope of the chaotic information carrier for the first predetermined frequency range is determined based on a set of parameters which include a first set of values.

Abstract: A spread spectrum modulator converts input sequences composed of digital symbols into n?2 spread-spectrum sequences. The spread spectrum modulator can generate spreading code and can combine the spreading code with the input sequences to produce the n spread spectrum sequences for transmission from n respective antennas of a radio transmitter. Each spread spectrum sequence corresponds to a sum of at least two contributions mutually shifted by a time substantially less than the duration of a symbol, each contribution being the product of a version of one of the n input sequences times the spreading code.

Abstract: An apparatus and method is provided for dynamic range power control of a wireless downlink communication signal, such that target signal quality adjustments are held temporarily when it is apparent that transmit power control commands will not produce the desired response at the transmitting station. Comparisons of measured received signals to thresholds are performed to determine whether the transmitting station has either reached the maximum or minimum transmit power, in which case the target signal quality adjustment is controlled accordingly. When normal transmit power is detected, the target signal quality adjustments are allowed to resume as usual.

Abstract: The disclosure relates to a method for generating UWB waveforms, each comprising a sequence of pulses, the method comprising: generating consecutive elementary pulses having durations corresponding to setpoint durations and a constant amplitude, amplifying each elementary pulse separately as a function of a respective setpoint amplitude, and combining the amplified elementary pulses to obtain a waveform successively comprising each of the amplified alternately positive and negative, elementary pulses.

Abstract: A high-speed transmitter and receiver are provided. In one embodiment, a transmitter comprises a baseband processor structured to receive data and to convert the data into a multiplicity of high and low signal values, with each high and low signal value having a first timing interval. A local oscillator generates a clock signal at a second timing interval and a digital circuit combines the high and low signal values with the clock signal to produce a transmission signal directly at a transmission frequency. A receiver is configured to receive the signal. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

Abstract: Direct sequence spread spectrum communications can use composite codes and can operate at a plurality of different chipping rates. The composite codes can be formed using a plurality of component codes, wherein the component codes can be relatively prime and at least one of the nominal lengths of the component codes can include a plurality of prime number multiplicands. The chipping rate and code length can be reduced by dividing a master rate by one or more of the prime number multiplicands. Symbol timing and time division multiple access timing can be tied to epochs of the component codes.

Abstract: An approach is provided for performing control signaling. Data and control information are received. The control information is orthogonalized using block-level spreading. The data and the orthogonalized control information are multiplexed at a symbol-level.

Abstract: In a communication system including a plurality of pairs of a transmitting device 2 and a receiving device 3, the transmission performance in the pairs is to be improved. The transmitting device 2-k transmits a transmission signal sk(t) to the receiving device 3-k a plurality of number of times. The receiving device 3-k updates the weight matrix Wk and the hopping pattern Pk used by the FIR filter which performs filtering on the transmission signal rk(t) at a predetermined time interval. The receiving device 3-k transmits the updated hopping pattern Pk to the transmitting device 2-k. The transmitting device 2-k receives the hopping pattern Pk to be used for subsequent spread spectrum.

Abstract: A communications network and method thereof include a base station controller configured to provide a repetition period of a primary synchronization channel to be equal to a predetermined integer value times a scrambling code length of the scrambling code of a common pilot channel. A user equipment in the network is configured to search for a known sequence comprising the primary synchronization channel to select a cell and a corresponding sub-frame/symbol timing from the selected cell.

Abstract: A method and system for encoding and determining labels in a Dual Polarization (DP) Quaternary Phase Shift Keying (QPSK) signal is provided. A label frame, signature sequence, and data payload are combined using a complementary constant-weight code encoding (CCWC) encoder, the output of which is deinterleaved and differentially precoded to generate a polarized tributary of a DP-QPSK signal. This encoding can be duplicated for a second tributary of the DP-QPSK signal. The label can be determined using one or more polarizers and corresponding low-speed photodetectors, each applied to a copy of the DP-QPSK signal. The strongest output of the photodetectors is then used to determine the label. Alternatively, the DP-QPSK signal can be viewed as having XI, XQ, PH, and PV tributaries. These tributaries can then be translated into XI, XQ, YI, and YQ tributaries are encoded into a standard DP-QPSK signal.