Abstract: Embodiments of a spread-carrier self-detecting code (SCSDC) receiver with summed-delay processing (SDP) and method are generally described herein. In some embodiments, the SCSDC-SDP receiver is arranged to generate a chip-matched filter output from a received spread-spectrum signal and perform SDP on the chip-matched filter output with a plurality of delay-processing chains. The SDP may include multiplying a conjugated and delayed chip-matched filter output with the chip-matched filter output and applying a code-matched filter that is matched to a delay-multiplied code. The outputs from the code-matched filters of each delay-processing chain may be coherently combined to provide an output having correlation peaks for use generating frequency error and timing information.

Abstract: Systems and methods for communication using hybrid signals are disclosed. In one aspect an apparatus for communication includes a processing system configured to encode a first set of information in a plurality of symbols and to encode a second set of information according to a spacing among the symbols. The apparatus may further comprise a transmitter configured to transmit to a device the symbols with the spacing among the symbols. In another aspect, an apparatus for communication includes a processing system configured to decode a first set of information from a plurality of symbols encoded with the first set of information or a second set of information from a spacing among the symbols by determining the spacing among the symbols. The apparatus may further comprise a receiver configured to receive the symbols via a wireless communication.

Abstract: A mobile terminal having a receive diversity function using a plurality of receive antennas, having a calculation section which combines respective level measurement results of the receive antennas and calculates a level measurement value after being combined as the level measurement result of the mobile terminal.

Abstract: A signal processing system and method for a GNSS digital signal wherein a carrier-stripped GNSS signal, is sampled according to a variable rate, determined by the code NCO, and including a timing circuit arranged to generate a timestamp code determining the sampling time of at least one of the samples in the buffer memory. By taking code samples in this way it is possible to transfer the samples asynchronously to a separate processor for the search task to be performed, for example an asynchronous parallel correlator implemented in the same silicon in hardware, or a media processor such as a graphics accelerator implemented in the same device or a separate physical device.

Abstract: A MIMO receiving apparatus that can demodulate a spatially multiplexed signal without using any division operation requiring a large quantity of operation resources. In the MIMO receiving apparatus, stream separation section (105) separates a spatially multiplexed signal into a plurality of streams based on numerator submatrix A. Numerator submatrix A is determined according to channel matrix H and a canceller scheme and corresponds to a numerator of stream separation matrix S that equalizes the phase and amplitude of the spatially multiplexed signal. Denominator part calculation section (108) calculates a denominator (denominator coefficient) of stream separation matrix S and correction section (117) corrects a threshold determined according to a modulation scheme of the spatially multiplexed signal using the denominator (denominator coefficient) of stream separation matrix S.

Abstract: Techniques are disclosed for determining which channelization codes are used for an interfering HS-PDSCH transmission without knowing whether a neighboring UE targeted by that transmission has had its 64QAM capability activated by higher layer signaling. The average amplitude is measured for each of several possible groups of channelization codes for each of one or more nearby UEs that might be the targets of interfering HS-PDSCH messages. Testing whether the amplitude is approximately the same across the codes in a possible combination of channelization codes yields a metric value that indicates whether that particular combination of codes is likely to be transmitted to a given UE. A second metric that detects the most likely modulation for possible groups of channelization codes is also calculated. The metrics are combined to determine which combination of channelization codes and modulation scheme is most likely being used for addressing the neighboring UE.

Abstract: One embodiment of the present invention provides a signal-recording system. During operation, the system receives a plurality of radio frequency (RF) signals, separates the RF signals to obtain a first group of RF signals in a first RF band and a second group of RF signals in a second RF band, and simultaneously down-converts the first group of RF signals to a first group of low intermediate-frequency (low-IF) signals in a first IF band and the second group of RF signals to a second group of low-IF signals in a second IF band. The system further converts the first group of low-IF signals and the second group of low-IF signals to the digital domain, and simultaneously processes all of the converted low-IF signals.

Abstract: This invention teaches a way to multiplex and de-multiplex unipolar signals using spread spectrum methods. While bipolar spread spectrum signal multiplexing may be used in may applications, for example for systems using radio signals, when using unipolar signals there is a loss of orthogonally which makes the standard algorithms unworkable. This invention teaches a method to recover orthogonally and make spread spectrum multiplexing useful for unipolar signals. One example is in the measurement of optical absorbance along multiple paths simultaneously using light signals, as for functional near infrared spectroscopy (fNIRS).

Abstract: Methods and apparatus for dynamically compensating for the effects of interference between multiple wireless communications apparatus. In one embodiment, the method comprises providing a first wireless communication apparatus operating in a first band and a second wireless communication apparatus operating in the same first band (or proximate to the first band and with a comparatively high transmitter power), where the second wireless communication apparatus operates according to a different communication protocol than the first wireless communication apparatus and further change in physical configuration with respect to one another. Based on the physical configuration, interference is compensated for between the first wireless communication apparatus and the second wireless communication apparatus “on the fly” by selecting and operating according to one of a plurality of operational protocols.

Abstract: A surface acoustic wave (SAW) correlator spread-spectrum (SS) receiver is disclosed which utilizes a first demodulation stage with a chip length n and a second demodulation stage with a chip length m to decode a transmitted SS signal having a code length l=n×m which can be very long (e.g. up to 2000 chips or more). The first demodulation stage utilizes a pair of SAW correlators which demodulate the SS signal to generate an appropriate code sequence at an intermediate frequency which can then be fed into the second demodulation stage which can be formed from another SAW correlator, or by a digital correlator. A compound SAW correlator comprising two input transducers and a single output transducer is also disclosed which can be used to form the SAW correlator SS receiver, or for use in processing long code length signals.

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 second 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. The third sequence is a subset of bits from the first sequence.

Abstract: A receiver may comprise a sequence estimation circuit and operate in at least two modes. In a first mode, the sequence estimation circuit may process OFDM symbols received on a first number of data-carrying subcarriers to recover a number of mapped symbols per OFDM symbol that is greater than the first number. In a second mode, the sequence estimation circuit may process OFDM symbols received on a second number of data-carrying subcarriers to recover a number of mapped symbols per OFDM symbol that is equal to the second number. The second number may be equal to or different from the first number. While the receiver operates in the first mode, the sequence estimation circuit may be operable to generate candidate vectors and process the candidate vectors using a controlled ISCI model to generate reconstructed physical subcarrier values.

Abstract: Methods implementable in a computer system for simulating the transmission of signals are disclosed. The disclosed techniques simulate the effect of the transmitter as well as the channel on a positive and negative pulse, which assures that asymmetry in the transmitter is captured. The resulting positive and negative pulse responses are then used to generate two separate PDFs: one indicative of received logic ‘1’s and another indicative of received logic ‘0’s at a point in time. Generating a plurality of such PDFs at different times allows the reliability of data reception to be assessed, and appropriate sensing margins to be set at a receiver, without the need to simulate the transmission of a very long random stream of data bits.

Abstract: Apparatus, methods, and systems are disclosed, including, for example, a data receiver to receive a calibration voltage and a reference voltage to calibrate the data receiver. The output of the data receiver is provided to a first ripple counter that counts the outputs from the data receiver and provides an output count. The ripple counter may count either ones or zeros. A second ripple counter counts the number of a clock signals over the same period of time. The output count is either multiplied by two or the count of clock signals is divided by two. A ripple comparator may then compare the outputs and adjust the reference voltage based upon the comparison results.

Abstract: In accordance with the teachings described herein, system and methods are provided for a GPS PRN code interpolation scheme with a reduced memory requirement. An example GPS receiver system may include a memory, a local PRN code generator, and an interpolator. The memory may be used to store GPS PRN code received from a global positioning satellite. The local PRN code generator generates a replica PRN code having a repeating code that includes at least a first epoch and a second epoch. The interpolator determines an offset point in the first epoch of replica PRN code and interpolates the replica PRN code at a predetermined sample rate to generate an interpolated replica PRN code for use in correlating with the GPS PRN code.

Abstract: A receiver has a bandwidth. The receiver includes paths, a first receiver module, an enable module, and a second receiver module. The paths are configured to be enabled to receive signals. The first receiver module is configured to, prior to the receiver receiving the signals, detect a number of the paths that are enabled to receive a signal. The enable module is configured to, based on the number of the paths detected to have been enabled (i) determine if the signals to be received by the receiver are receivable by a number of the paths less than the number of the paths detected to have been enabled, and (ii) disable, based on a result of the determination, one or more of the paths detected to have been enabled. The second receiver module is configured to, based on the number of the paths enabled, adjust the bandwidth of the receiver.

Abstract: The invention relates to a method for acquisition of a signal (2) emitted by a satellite, by a receiver in a satellite Positioning System using a multi-code correlation and a multi-frequency correlation, also comprising the step in which if the error induced at the output from a first frequency-augmented correlator (14) at each instant in an integration period is greater than the code space between code correlators (12), the summated results of the first frequency-augmented correlator (14) are transferred to the summated results of a second frequency-augmented correlator (14), the second frequency-augmented correlator (14) using the same frequency-shift as the first frequency-augmented correlator (14) and being associated with a second code correlator (12) that is shifted by the code space from the first code correlator (12) with which said first frequency-augmented correlator (14) is associated.

Abstract: A method for noise rise estimation in a wireless communication system comprises receiving (210) of radio signals. An interference whitening (212) is performed. A useful signal power for a first user after the interference whitening is determined (214) for a plurality of time instances. Furthermore, a first user noise floor compensation factor is derived (216) based on combining weights for the first user used in the interference whitening. A probability distribution for a compensated useful signal power for the first user is estimated (218). A conditional probability distribution of a noise floor measure is computed (220). A noise rise measure for the first user is then calculated (222) based at least on the compensated useful signal power for the first user and the conditional probability distribution of a noise floor measure.

Abstract: A method for detecting possible correlations between signal patterns of a power signal used by an electronic device during execution of operations, including setting couples of windows including respective pairs of sequences of the sampling values. The method includes computing values of correlations between the respective pairs of sequences. Each values may be determined by computing a maximum value of correlation between one sequence of a couple and a plurality of sequences of sampled values included in corresponding moving windows.

Abstract: A device for decoding code symbols which are interfered with a distortion during a predetermined distortion time interval includes a reliability information generator to provide reliability information based on the code symbols and a decoder to decode the code symbols into code words. The decoder is configured to decode the code symbols based on weighted reliability information, wherein the weighted reliability information is generated from the reliability information by applying a first weight during times not coinciding with the distortion time interval, and by applying a second weight different from the first weight during times coinciding with the distortion time interval.

Abstract: A receiver architecture for processing spread spectrum signals. The receiver has an RF front end to receive and down convert a broadcast signal to an intermediate frequency carrier. The IF signal is digitized and provided to a processor (which may be a software-driven DSP, an ASIC or other embodiment) for processing. A given IF carrier is removed and the signal is low pass filtered. The signal is provided to a number of channels, each, for example, correspond to a unique transmitter. On each channel the sample rate is reduced to a predetermined fixed rate with timing mismatch compensated. The Doppler frequency shift, as estimated for the channel, is removed succeedingly. A locally generated copy of the spreading code used by the transmitter is applied to the carrier and Doppler removed signal at the predetermined fixed sample rate. The de-spread signal is used to provide estimates of the Doppler shift and for subsequent sample selection.

Abstract: A detector receives detects a first known signal in a packet signal. An LTF correlation unit performs correlation processing on the packet signal received by a receiving unit. Upon detecting the arrival timing, an update correlation unit terminates a first window and performs correlation processing on the packet signal received by the receiving unit, in a second window. When correction timing is detected and when correction timing is more likely to be accurate than the arrival timing, an estimation unit changes the correction timing to the arrival timing; when the arrival timing is more likely to be accurate than the correction timing, the estimation unit maintains the arrival timing.

Abstract: A mobile electronic device that includes a circuitry configured to acquire synchronization with a spreading code of an intermediate frequency signal that is obtained by converting a frequency of a received signal from a satellite in a global positioning system into a predetermined intermediate frequency, demodulate a message included in the intermediate frequency signal, output a primary signal to a predetermined signal line, and attach a predetermined header to a secondary signal and output the result to the predetermined signal line, and includes a display unit configured to display data corresponding to the primary signal and the secondary signal, such that the primary signal includes results of measuring one of position, velocity, and time of the mobile electronic device based on the message that is demodulated by the circuitry, and that the secondary signal includes the intermediate frequency signal.

Abstract: A signal receiver used in a satellite communication system is provided. The signal receiver comprises a first type code generator, a second type code generator, a composite code generator, a correlation module and a determining module. The first type code generator generates a first type code corresponding to a first type signal. The second type code generator generates a second type code corresponding to a second type signal and having a code length N-time longer than that of the first type code. The composite code generator generates a composite code by superimposing N successive first type codes on the second type code. The correlation module correlates the composite code with a cell of a received signal to generate correlation results. The determining module determines a type of the received signal according to correlation results of the composite code with the received signal.

Abstract: An antenna beam scan unit includes: a Rotman lens that performs power division and synthesis between plural antenna ports and three or more beam ports; plural antenna elements which are connected to the respective antenna ports and to or from which radio waves are inputted or outputted; plural amplifiers that are connected to the respective beam ports of the Rotman lens and perform amplitude modulation on a signal; input paths for a transmission signal disposed in association with the amplifiers; switches for switching the input paths; and a beam control unit. The input paths include first paths and second paths on which a signal that is out of phase with a signal on the first paths is produced. The beam control unit selects two adjoining beam ports, and can switch the first paths and second paths as the input paths for the two beam ports.

Abstract: A method for receiving Acknowledgement/Negative acknowledgement (ACK/NACK) information in a mobile communication system includes receiving a first signal including first spread ACK/NACK information and second spread ACK/NACK information from a first antenna set of a transmitting end in an orthogonal frequency division multiplexing (OFDM) symbol; receiving a second signal including third spread ACK/NACK information and fourth spread ACK/NACK information from a second antenna set of the transmitting end in an OFDM symbol; and de-spreading at least the first and third spread ACK/NACK information or the second and fourth spread ACK/NACK information for identifying the ACK/NACK information.

Abstract: A correlation calculating method of correlating a received code signal obtained by demodulating a received signal, which is a signal obtained by receiving a positioning satellite signal, with a replica code signal is provided which includes: correlating values of the replica code signal in a chip period with values of the received code signal at first to n-th arrival times obtained by varying an arrival time of the chip period by 1/n chip (where n is an integer equal to or greater than 2); and acquiring a correlation calculation result at a 1/n chip interval by synthesizing the correlation calculation results.

Abstract: A method of operating a transmitter (FIGS. 3A and 5A) is disclosed. The method includes receiving a sequence of data bits (DATA), wherein each data bit has a respective sequence number. A first data bit of the sequence is spread (508) with a first spreading code (504) determined by the sequence number (502) of the first data bit. A second data bit of the sequence is spread (508) with an inverse of the first spreading code (506) determined by the sequence number (502) of the second data bit. The first and second data bits are modulated (510) and transmitted (516) to a remote receiver.

Abstract: A signal processor for GPS or other GNSS radiolocalization systems, includes a RAM pre-correlation buffer which is filled in sync with the code NCO, thus all sample alignment in the buffer is fixed The device further includes an amplitude compressor to limit the size of the buffer memory and is optimized to provide data to the following DFT unit in small bursts that can be processed in real time without the need for intermediate buffers. Thanks to these features the processor limits the amount of fast intermediate memories, is simpler and has lowerpower consumption.

Abstract: A method for acquiring a direct sequence spread spectrum signal, which is transmitted on a carrier frequency and is modulated with a code signal of length equal to Nc chips, for determining a code delay of the spread spectrum signal and a Doppler shift with respect to the carrier frequency, the determination being performed on a discrete two-dimensional space of M possible code delays and F possible frequency shifts, includes: receiving and sampling the spread spectrum signal to obtain a sampled spread spectrum signal; performing a despreading operation of the sampled spread spectrum signal with a local replica signal of the code signal, by performing the despreading for a plurality of possible code delays between the sampled signal and the replica signal; and performing a parallel frequency search on the result of the despreading step, by performing a step of computing a Fourier transform on the result. The Fourier transform is a fractional Fourier transform.

Abstract: In some embodiments an adaptive clock controller is to determine clock interference associated with a channel changing pattern for a radio in a computing platform, and to determine an earliest switching time of a clock of the computing platform. A clock generator is to change a frequency of the clock in response to the determined clock interference and in response to the earliest switching time. Other embodiments are described and claimed.

Abstract: Apparatus and method for providing correlation in a CDMA receiver. A Generic Correlation Coprocessor comprises one or more correlation blocks. Each correlation block comprises a correlation input buffer coupled to one or more correlators. The correlators are coupled to an interpolator input buffer and to a correlator output buffer. One or more interpolators are coupled to the interpolation input buffer and to the correlation output buffer. The correlators correlate the received signal with PN codes to produce a correlated signal. The correlated signal is stored in the correlator output buffer and/or the interpolation input buffer, and provided from the interpolation input buffer to the one or more interpolators. The one or more interpolators interpolate the correlated signal to produce an interpolated signal. The interpolated signal is stored in the correlator output buffer. Signals are provided from the correlator output buffer to other receiver processing systems.

Abstract: A decoding apparatus and method of a terminal in a wireless communication system are provided. A carrier to interference and noise ratio (CINR) estimator estimates a CINR value of a received signal, and a controller generates a modulation and coding scheme (MCS) level candidate set satisfying the estimated CINR value and a target packet error rate (PER) based on a look-up table. A decoder switch determines if an MCS level of a burst is included in the MCS level candidate set when the burst having no connection identifier (CID) information exists in a corresponding frame, and determines to decode the corresponding burst if the MCS level of the burst is included in the MCS level candidate set and to discard the burst otherwise.

Abstract: Synchronized broadcast transmits a same broadcast content using a same waveform from multiple transmitters. Transmitters each apply a same spreading code for broadcast transmissions. In a spread-spectrum communication system having a time division multiplexed forward link, a synchronized broadcast transmission is inserted into a broadcast slot. One embodiment employs an Orthogonal Frequency Divisional Multiplex (OFDM) waveform for the synchronized broadcast. An OFDM receiver is then used to process the received synchronized broadcast transmission. An alternate embodiment implements a broadcast Pseudo-random Noise (PN) code for use by multiple transmitters. An equalizer is then employed to estimate the synchronized broadcast transmission.

Abstract: A method and apparatus is provided for intra-PIT signal decomposition of a signal received with RF front end hardware. The method begins by aligning a signal received by RF front end hardware into integer multiples of a duration of a pseudorandom noise code sequence. A search grid is computed based on an integer multiple of the aligned signal. A plurality of initial ray parameters associated with the computed search grid is coarsely estimated. Using the coarsely estimated plurality of initial ray parameters, a fine estimation of the plurality of initial ray parameters is initiated utilizing stochastic search and optimization techniques. A stopping criteria statistic is computed by comparing a peak power of the search grid with a noise power present in the search grid. Finally, in response to determining the stopping criteria statistic being less than a stopping criteria threshold, processing a next integer multiple of the aligned signal.

Abstract: There is described an electronic system including a first electronic device and a second electronic device communicating with each other. The first electronic device includes a first output unit, a first communication unit, and a first controller automatically transmitting supplementary information related to multimedia contents to the second electronic device through the first communication unit while playing the multimedia contents through the first output unit. The second electronic device includes a second output unit, a second communication unit, and a second controller outputting supplementary contents, related to the multimedia contents, through the second output unit on the basis of the supplementary information received from the first electronic device.

Abstract: A wireless transceiver includes a receiver and a transmitter, the receiver and transmitter implemented to have multiple receive and transmit channels respectively, to provide multiple-input multiple-output (MIMO) capability. In an embodiment, the transceiver is implemented to include two transmit channels and two receive channels. Some blocks/circuitry of each of the receive and transmit channels are implemented with reduced area and current consumption, with a corresponding increase in noise. In a single-input single-output (SISO) mode of operation, the receiver combines the output of both the receive channels to compensate for the increase in noise due to the implementation with smaller area and lower current consumption. Similarly, the transmitter combines the output of both the transmit channels to compensate for the increase in noise. The transceiver operates with no signal degradation in SISO mode, and with a small degradation in signal quality in the MIMO mode.

Abstract: A direct-sequence spread spectrum (DSSS) receiver may be operable to process signal samples in frequency domain utilizing a prime factor fast Fourier transform (FFT) circuit and a pseudorandom noise (PRN) code. The DSSS receiver may be operable to transform the signal samples into FFT signal samples using the prime factor FFT circuit, transform the PRN code into a FFT PRN code using the prime factor FFT circuit and multiply the FFT signal samples with the FFT PRN code using the prime factor FFT circuit. The DSSS receiver may be operable to inversely transform the multiplied FFT signal samples into correlated signal samples using a prime factor inverse FFT (IFFT) implemented by the prime factor FFT circuit. The prime factor FFT circuit may comprise a prime length FFT core, a FFT memory, a register bank, a switch, a multiplier and a FFT controller.

Abstract: Techniques to improve the acquisition process in a spread spectrum environment. The signals from different CDMA systems are spread with different sets of PN sequences, with the PN sequences in each set being uncorrelated to the PN sequences in the other sets. The mobile station can attempt to acquire the pilot signal by processing the received signal with a first set of PN sequences corresponding to a first hypothesis of the particular signal being acquired. If acquisition of the pilot signal fails, a second set of PN sequences corresponding to a second hypothesis is selected and used to process the received signal. The PN sequences in the second set are uncorrelated to the PN sequences in the first set.

Abstract: A code phase is detected on the basis of a signal received by an RF receiving circuit unit which is a receiving unit that receives a GPS satellite signal. When the code phase is within a predetermined edge of a PRN code, a control of suppressing intermittent driving of the RF receiving circuit unit is performed.

Abstract: A CDMA receiver computes an accurate estimate of the data to pilot power ratio. First, a biased estimate of the data to pilot power ratio is obtained from the data channel. A multiplicative correction factor is then computed from the pilot channel, and applied to the biased data to pilot power ratio estimate.

Abstract: Provided is a pulse modulation circuit capable of generating a pulse modulation signal with a steep rise and a desired pulse width at a desired timing not depending on a transmission signal sequence. In this circuit, a control signal generation unit (110) generates a first control signal if transmission data (S11) is “1” and a second control signal if the transmission data (S11) is “0.” The control signal generation unit (110) controls an oscillator (1200) of an intermittently operating circuit (120) to be at an oscillation state for outputting a desired first oscillation signal while the first control signal is turned ON and controls the oscillator (1200) to be at an idling state for outputting a second oscillation signal having a lower amplitude than the first oscillation signal while the second control signal is turned ON.

Abstract: A receiving system dynamically searches the communications band for transmissions of messages having the same nominal communications parameters, including the use of the same spreading code, but having potentially different specific frequencies and code-phases. The receiver, which is independent of the transmitters, samples the communications band at each code-phase of the spreading code over a span of downconverted transmission frequencies. When a message element is detected at a particular code-phase and frequency, it is forwarded to a demodulator that demodulates the message and sends it to its intended destination. In a preferred embodiment, a progressive Fourier Transform is used to incrementally determine the power level at each successive code-phase at a given frequency, thereby substantially reducing the time required to search for transmissions at each discrete code-phase.

Abstract: A method for receiving modulation signals includes receiving a plurality of multiplexed modulation signals each transmitted from multiple antennas of a communication partner, wherein each modulation signal includes a pilot symbol sequence consisting of plural pilot symbols used for demodulation. Each of the pilot symbol sequences is inserted at the same temporal points in the each modulation signal. The pilot symbol sequences are orthogonal to each other with zero cross correlation among the plurality of modulation signals, each pilot symbol having a non-zero amplitude, the quantity of the plural pilot symbols in each sequence being greater than the quantity of the plurality of transmitted modulation signals.

Abstract: Embodiments of a receiver for using a first oscillator signal provided by a crystal resonator to support multiple, different functionalities are provided. The receiver comprises a phase-locked loop (PLL) configured to provide a second oscillator signal based on the first oscillator signal provided by the crystal resonator; a first mixer configured to mix a received signal received over a first input path with the second oscillator signal received over a second input path to provide a first frequency-shifted signal; and an automatic frequency controller (AFC) configured to estimate a frequency offset of the second oscillator signal and adjust the PLL to compensate for the frequency offset. The receiver further can include solutions for mitigating potential sources of noise caused by the frequency of the first oscillator signal not being compensated for by the AFC.

Abstract: An apparatus includes a transmit diversity encoder configured to use a block code of a length greater than one for encoding at least two consecutive symbols. A first symbol of the at least two consecutive symbols is dedicated to a first user and the second symbol of the at least two consecutive symbols is dedicated to a second user.

Abstract: The invention includes a method for transmitting and detecting high speed Ultra Wideband pulses across a wireless interface. The transmitter includes a serializer and pulse generator. The receiver comprises a fixed delay line, multiplier, local serializer (with a sequence matching the transmitter), digital delay lines, low noise amplifier and logic fan-out buffer along with an array of D flip-flop pairs. Each flip-flop pair is enabled, at fixed time increments, to detect signals at a precise time; the timing is controlled by the pseudo-random sequence generated by the local serializer. A local tunable oscillator is controlled by detecting the phase change of the incoming signal and applying compensation to maintain the phase alignment and clock synchronization of the receiver to the clock reference of the transmitter. The invention uses a pair of pulses with a fixed delay and then relies on mixing the two to provide better noise immunity.

Abstract: Method and apparatus for high rate code-division multiple access wireless communication is described. Each of a channel encoded data is modulated by an associated code having a small number of pseudo-noise spreading chips per orthogonal waveform period, thus producing a set of streams of modulated symbols. Each of the set of streams of modulated symbols is then gain adjusted, and combined to yield two streams of combined symbols. The combination is the set of streams is carried out to reduce a peak-to-average ratio of the transmission. The resulting two combined symbol streams are modulated by a complex multiplyer using a user long code and a pseudorandom spreading code (PN code) and upconverted for transmission.

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 waveform-adaptive ultra-wideband (UWB) transmitter and noise-tracking UWB receiver for use in communications, object detection and radar applications. In one embodiment, the output of an oscillator is gated by a low-level impulse generator either directly or through an optional filter. In a special case of that embodiment wherein the oscillator is zero frequency and outputs a DC bias, a low-level impulse generator impulse-excites a bandpass filter to produce an UWB signal having an adjustable center frequency and desired bandwidth based on a characteristic of the filter. In another embodiment, the low-level impulse signal is approximated by a time-gated continuous-wave oscillator to produce an extremely wide bandwidth pulse with deterministic center frequency and bandwidth characteristics. The low-level impulse signal can be generated digitally. The UWB signal may be modulated to carry data, or may be used in object detection or ranging applications.