Abstract: A receiving apparatus 10 includes an adaptive array antenna 11, a reference signal synthesizer 15 that calculates a synthesized reference signal by multiplying a reference signal portion of each layer by an orthogonal signal to synthesize proximity reference signal portions of different resource elements and multiplies a known reference signal by the orthogonal signal, a weight calculator 16 that calculates an adaptive array weight from the synthesized reference signal and a known reference signal multiplied by the orthogonal signal, a weight synthesizer 17 that calculates a synthesized reception signal by multiplying the reference signal portion by the adaptive array weight to perform an antenna synthesis, a channel estimator 18 that estimates a propagation path from the synthesized reception signal and the known reference signal multiplied by the orthogonal signal, and a channel equalizer 19 that implements a channel equalization from the synthesized reception signal and the propagation path.

Abstract: A clock oscillator includes a high speed oscillator generating a high speed clock signal and comprising a digital trimming function; a counter receiving said high speed clock signal at a clock input; a time base having a low drift and controlling said counter, wherein the counter generates a difference between a reference value and a counter value; and a digital integrator receiving said difference value and providing trimming data for said high speed oscillator.

Abstract: A sliding intermediate frequency (IF) receiver and a sliding IF reception method are provided. A first local oscillation signal and a second local oscillation signal may be generated, based on a division ratio of a frequency of the first local oscillation signal to a frequency of the second local oscillation signal that is determined in advance so that an amount of power to be consumed or an error rate of the sliding IF receiver is optimized. A received input signal may be converted to a first IF signal, based on the first local oscillation signal, and the first IF signal may be converted to a second IF signal, based on the second local oscillation signal.

Abstract: A sigma delta receiver achieves increased stability and noise reduction. The sigma delta receiver includes a first integrator stage, an isolation stage, a second integrator stage, and a quantization stage. The first integrator stage receives an analog radio frequency (RF) signal from an antenna and generates an analog baseband signal based on the analog RF signal. The isolation stage is coupled to an output of the first integrator stage. The isolation stage receives the analog baseband signal from the first integrator stage and amplifies the analog baseband signal. The second integrator stage is coupled to an output of the isolation stage to receive the analog baseband signal. The second integrator stage further amplifies the analog baseband signal. The quantization stage converts the analog baseband signal to a digital signal, and outputs the digital signal.

Abstract: A terminal-to-terminal communication method and a terminal. The method includes: receiving, by a first terminal, data in a first OFDM symbol, where the data is sent by a second terminal in a second OFDM symbol, the first OFDM symbol is synchronized by the first terminal according to first timing information sent by a base station, and the second OFDM symbol is synchronized by the second terminal according to second timing information sent by the second terminal; and if the first OFDM symbol is not synchronized with the second OFDM symbol, skipping processing, by the first terminal, residual data that is sent by the second terminal in the second OFDM symbol and that exceeds a time indicated by the first OFDM symbol.

Abstract: Using a clock circuit, a clock signal is generated at a base frequency. A frequency adjustment circuit selects, based upon a frequency offset value, a particular frequency adjustment value from a plurality of frequency adjustment values. An adjusted clock signal is provided that has a frequency corresponding to the base frequency as modified by the particular frequency adjustment value. Wireless communication signals are received at a wireless communication circuit. From the communication signals, a set of received wireless communication pulses are identified that have a pulse repetition frequency that corresponds to the adjusted clock signal. A distance ranging protocol is applied, using a processing circuit, to the identified set of received communication pulses.

Abstract: Disclosed are a method and apparatus for processing a transmission signal using a window function that changes a spectrum characteristic of a symbol. A transmission apparatus includes a symbol generator that generate a plurality of consecutive symbols, and a symbol windowing processor that is coupled with the symbol generator. The symbol windowing processor applies a first window function and a third window function that uses a difference between the first window and a second window, and changes a spectrum characteristic of each of the plurality of consecutive symbols, and processes neighboring symbols from among the plurality of consecutive symbols of which spectrum characteristics are changed, such that the symbols partially overlap one another.

Abstract: A method for adapting a mixed signal Infinite Impulse Response (IIR) Decision Feedback Equalizer (DFE) using pivot taps and monitor taps is disclosed. The method includes, for a given IIR path for a received signal, updating gain of the given IIR path using a respective pivot tap error-data correlation with a first Least Mean Square (LMS) update equation; and updating a time constant of the given IIR path using a respective monitor tap error-data correlation with a second LMS update equation.

Abstract: Systems and methods for controlling a power amplifier includes combining a digital modulated data signal with a digital bias signal to generate a combined digital signal, the digital bias signal generated based on an envelope for the modulated data signal; converting, by a digital-to-analog converter, the combined digital signal into a combined analog signal, the combined analog signal comprising an analog modulated data signal and an analog envelope bias signal; and separating the analog modulated data signal and the analog bias signal onto separate signal paths, wherein the converting is performed using a single digital-to-analog converter.

Abstract: A server system includes a common power bus, a power supply to provide direct current (DC) power through the common power bus, at least one node including a processor to receive the DC power through the common power bus, a transmitter capacitive coupled to the common power bus to transmit a power information signal from the power supply through the common power bus, and at least one receiver capacitive coupled to the common power bus to receive the power information signal transmitted by the transmitter and to provide the received power information signal to the at least one node. A plurality of buffers respectively coupled between the common power bus and each of the power supply and the at least one node provide path separation for high frequency and low frequency currents.

Abstract: A method is provided for transmission of an OFDM signal, wherein pre-transmission processing includes: mapping data representative of a source signal to complex symbols Xn, 0<=n<M, belonging to a constellation; transforming M symbols Xn into M corrected symbols X?n, such that X?n=Xn+dn, wherein dn is a complex correction; and mapping M corrected symbols X?n to M from N carriers of an OFDM modulator to generate an OFDM signal, M<=N. The transformation includes initializing an accumulator, and, for each carrier of order n: accumulating at J samples of the n-order carrier mapped by X?n; detecting a peak on the J samples accumulated at order n?1 and comparing the peak with the corresponding time sample of the n-order carrier delivering complex correction control information; and determining the correction value dn to obtain the corrected symbol X?n according to the correction control information.

Abstract: A method includes processing an input sequence of samples of an orthogonal frequency division multiplexing signal (OFDM) to reduce a peak to average power ratio (PAPR) of the OFDM signal with given constraints of an error vector magnitude (EVM) parameter and a spectral mask parameter for the OFDM signal during a first processing iteration. The method includes performing at least one other iteration of the first processing iteration on a subsequent time domain sequence generated in the first processing iteration to reduce the PAPR of the OFDM signal below a system target PAPR threshold and below threshold limits for the EVM parameter and the spectral mask parameter.

Abstract: The present invention relates to a modulation circuit of a digital transmitter, a digital transmitter, and a signal modulation method. The modulation circuit includes: a first synchronizing circuit and a digital modulator, where the first synchronizing circuit separately perform phase delay on a first local-frequency signal or a second local-frequency signal to obtain corresponding delay signals, and perform phase adjustment on a digital baseband signal by using the delay signals, to generate a first adjusted signal and a second adjusted signal; and the digital modulator modulates the first adjusted signal by using the first local-frequency signal, to generate a first radio-frequency signal, and modulates the second adjusted signal by using the second local-frequency signal, to generate a second radio-frequency signal.

Abstract: A first noise variance estimator calculates a first noise variance estimation value based on an channel estimation value of a received signal. A minimum mean squared error (MMSE) filter performs equalization on a residual interference component that is obtained by subtracting an interference component and desired signal component from the received signal. A second noise variance estimator calculates a second noise variance estimation value by using the equalized residual interference component that is output from the MMSE filter. A first noise variance selector and second noise variance selector select either one of the first or second noise variance estimation value, or selects a mean value of the two noise variance estimation values. A filter coefficient calculator calculates a filter coefficient based on a first selected noise variance value. An extrinsic LLR calculator calculates an extrinsic LLR by using a second selected noise variance value selected by the second noise variance selector.

Abstract: Multichannel signal generator performance characterization employs orthogonal modulation to characterize a relative performance of channels of a multichannel signal generator. The performance characterization includes generating a first signal in a first channel of the multichannel signal generator and generating a second signal in a second channel of the multichannel signal generator. The first and second signals include an orthogonal frequency-division multiplexing (OFDM) digital modulation having a first set of subcarriers assigned to the first signal and a second set of subcarriers assigned to the second signal. Performance characterization further includes combining the first signal and the second signal to produce a combined signal along with receiving and demodulating the combined signal according to the OFDM digital modulation using a digital receiver and determining a performance parameter of the second channel relative to the first channel from the received and demodulated combined signal.

Abstract: Methods, a base station and computer programs for performing multiple access in wireless OFDM cellular systems over multipath wireless channels considering both space and frequency domains, The base station 100 comprises a large number of antennas 103 in the form of a two-dimensional array and transmits a given number of signals to a number of users 106, so that each one receives its intended signal (or set of intended signals) without interference to/from the other users 106. The base station 100 includes a scheduler in space-time-frequency dimensions 101 as well as an orthogonal space-frequency processing technique 102 for addressing the users 106. The cellular scenario is assumed where the wireless channel 105 presents significant multipath, thereby resulting in multiple signal components being received by each user 106.

Abstract: An iterative method for synthesizing digital filters comprises the following steps: generation of a transmit filter intended to be applied to a signal to be transmitted; and generation of a receive filter intended to be applied to a received signal. The method comprises the following iteratively executed steps: convolution of the transmit filter and the receive filter in order to generate a transmission filter; determination of a criterion that is representative of the level of intersymbol interference on said transmission filter and whether the level of intersymbol interference is higher than a given level; calculation of an equalizing filter for the intersymbol interference; replacement of the transmit filter with the convoluted transmit filter having the equalizing filter or the replacement of the receive filter with the convoluted receive filter having the equalizing filter.

Abstract: A method of calibrating parameters for a polar transmitter (Polar TX) system includes receiving phase information derived from transmission information in a Polar TX for producing a radio frequency (RF) broadcast signal. An Inphase local oscillator (LO_I) signal and a quadrature phase local oscillator (LO_Q) signal are derived from a combination of a first signal and the phase information using a digital phase lock loop. A feedback receiver (FBR) receives the RF broadcast signal provided by the Polar TX. The LO_I signal and the LO_Q signal are mixed with the RF broadcast signal to obtain mixer output signals. RF path delay and IQ phase imbalance are concurrently determined as a function of the first signal and of the mixer output signals.

Abstract: A communication system that uses keyed modulation to encode fixed frequency communications on a variable frequency power transmission signal in which a single communication bit is represented by a plurality of modulations. To provide a fixed communication rate, the number of modulations associated with each bit is dynamic varying as a function of the ratio of the communication frequency to the carrier signal frequency. In one embodiment, the present invention provides dynamic phase-shift-keyed modulation in which communications are generated by toggling a load at a rate that is a fraction of the power transfer frequency. In another embodiment, the present invention provides communication by toggling a load in the communication transmitter at a rate that is phase locked and at a harmonic of the power transfer frequency. In yet another embodiment, the present invention provides frequency-shift-keyed modulation, including, for example, modulation at one of two different frequencies.

Abstract: An exemplary method is implemented by a radio frequency receiver for synchronizing the recovery of data carried by frames. An indication is generated from error correction of whether the error control coding in the receiver is capable of correcting all the errors induced by the channel within the frame. If the indication declares that all the errors are corrected, then the carrier frequency estimate associated with the error free frame is saved in memory and will be used to initialize the carrier recovery loop at the beginning of the following frames until such frequency estimate is declared unreliable. A new carrier frequency estimate is available at the end of each frame, and if such estimate is proven to be reliable for future use, the current estimate in memory will be overwritten by the new estimate and the freshness of the frequency estimate is extended.