Intel Corporation

Nxp B.v.

Intel Mobile Communications Technology Dresden Gmbh

Commsolid Gmbh

St-ericsson Sa

Intel Mobile Communications Gmbh

Blue Wonder Communications Gmbh

Shenzhen Goodix Technology Co., Ltd.

Intel Deutschland Gmbh

Andreas Bury

Volker Aue

Ismael Gutierrez

Yeong-Sun Hwang

Rajarajan Balraj

Axel Clausen

Michael Schmidt

Stefan Fechtel

Holger Neuhaus

Matthias Hofmann

Gunnar Nitsche

Kenan Kocagoez

Mathias Kurth

Johan Pean

Javier Mauricio Paredes Riano

Ingmar Groh

Tobias Seifert

The invention relates to an analog-to-digital converter (ADC). The objective of the invention to have an analog-to-digital converter with the capability of non-equidistant sample time spacing and minimizing energy consumption will be solved by an apparatus comprising a sigma-delta modulator and a sample-time-counter, both controlled by a sample clock, a next-sample-time-computation unit configured to compute a sample-time-counter value when a next digital output sample is requested, a sample-computation-trigger unit connected to the next-sample-time-computation unit configured to compare an actual sample-time-counter value with the sample-time-counter value when the next digital output sample is requested and to trigger a computation unit for calculating a next digital sample when requested and by powering off the sigma-delta modulator in intervals where its delivered samples are not used for any computed decimator output sample. The objective is also solved by a method using the aforementioned analog-to-digital converter.

Analog to digital converter

A receiver system includes an interface between a radio receiver on a radio frequency (RF)-side and a baseband receiver on a baseband (BB)-side. The receiver includes an antenna for receiving radio frequency signals and an analogue-to-digital converter for converting received analogue signals to digital signals. The digital signals are further processed in the baseband receiver by a digital signal processing unit. The analogue-to-digital converter is a sigma-delta converter, which includes a sigma-delta modulator on the RF-side and a decimation filter on the BB-side. The sigma-delta modulator and the decimation filter are connected only by single-bit in-phase (I) and quadrature (Q) streams output lines.

Interface between radio receiver and baseband receiver and a method for converting RF-signals to BB-signals

A method () of determining mutual information of a composite receive signal, the composite receive signal comprising a reference signal and a data signal, includes the following acts: estimating () a base metric of the composite receive signal based on the reference signal, the base metric being indicative of a channel quality; and determining () the mutual information based on the base metric and the data signal.

Method and device for determining mutual information

It is proposed a method for delay spread classification of an orthogonal frequency-division multiplexing signal (multiplexing signal), and a receiving device and a telecommunication device connected thereto, the multiplexing signal comprising at least a first multiplexing symbol comprising at least two first reference symbols in the frequency domain, the method comprising: receiving at least the first multiplexing symbol; demodulating at least the first reference symbols of the first multiplexing symbol; determining at least a first autocorrelation value by autocorrelating the demodulated first reference symbols in the frequency domain; computing the filtered output energy of the autocorrelation and classifying the delay spread by mapping the ratio of the output energy for the filters.

Delay span classification for OFDM systems using selective filtering in the frequency domain

A communication device is described comprising a receiver configured to receive a plurality of first reference signal values in a first subframe of a radio frame structure and to receive a plurality of second reference signal values in a second subframe of the radio frame structure, wherein the first subframe and the second subframe are separated by one or more subframes of the radio frame structure, a first filter configured to filter the plurality of first reference signal values received in the first subframe to generate a first channel estimate, a second filter configured to filter the plurality of second reference signal values received in the second subframe based on the first channel estimate to generate a second channel estimate and a processor configured to process received signals based on the second channel estimate.

Communication device and method for processing received signals

A communication device is provided comprising a radio frequency circuit configured to receive a first radio frequency signal and a second radio frequency signal. A baseband circuit configured to determine a gain level based on the first radio frequency signal. A clock circuit configured to generate a clock signal. The radio frequency circuit is configured to determine a gain adjusted signal based on the second radio frequency signal and on the gain level. The baseband circuit is configured to synchronize the clock signal based on the gain adjusted signal.

Communication device and method for performing radio communication

A method includes receiving at a receiver circuit a composite signal including non-interfered data resource elements and interfered data resource elements from a plurality of radio cells, and determining a first mutual information metric based on the non-interfered data resource elements. The method further includes determining a second mutual information metric based on the interfered data resource elements, and determining effective mutual information based on a combination of the first mutual information metric and the second mutual information metric.

Methods and devices for determining effective mutual information

The method comprises receiving a signal comprising a symbol-carrier matrix, the symbol-carrier matrix comprising a predetermined pattern of reference symbols, the reference symbols comprising a target reference symbol, determining a first channel estimate vector based on demodulating received reference symbols with known reference symbols, and determining a second channel estimate vector by multiplying the first channel estimate vector with an interference cancellation matrix, wherein the second channel estimate vector includes an interference cancelled channel estimate at a position of the target reference symbol.

Method and device for channel estimation with colliding interference cancellation

In 3GPP LTE, user equipment must be able to report reference signal received power (RSRP) measurement to the serving cell's base station. A low-complexity method for asynchronous RSRP measurement in an LTE user equipment receiver is provided which includes frequency shifting the received signal so that the upper or lower half band becomes centered around the DC frequency; decimating the received signal to a width of n&#xb7;2samples, n being the reference symbol spacing in the received signal; dividing the samples into n sample vectors with a length of 2each, superimposing the n sample vectors; and performing FFT operation on the superimposed signal.

Method and arrangement for asynchronous RSRP measurement in an LTE UE receiver

A mobile station receiving a signal from a base station experiences time/frequency varying channel conditions. In order to get the maximum throughput from a base-station, it is necessary to adjust the modulation and coding schemes to the actual channel quality. To do so, mobile receivers are required to probe the radio channel condition and feedback a limited set of estimated channel state information parameters such as CQI, RI, and PMI. The invention uses modulation-specific mutual information as a basic metric for CQI-PMI-RI computation to yield high bandwidth efficiency under both flat fading and interference conditions as well as time and frequency selective fading and interference conditions, at reasonable complexity.

Method and apparatus for determining channel state information

An LTE baseband receiver and a method for operating the receiver are provided. The receiver comprises a frequency selective interference estimator, an interference level averager and an interference assessor operative to control which output of the frequency selective interference estimator or the interference level averager is to be supplied to a soft-metric calculator. Frequency selectivity of the interference is assessed, and the best mode of interference estimation is selected to increase LTE receiver performance in loaded networks without impacting receiver performance in unloaded networks.

LTE baseband receiver and method for operating same

Orthogonal frequency division multiplexing (OFDM) has become a popular transmission method for high speed wireless radio transmission, due to its potential for low complexity of transmitters and receivers. A method and apparatus are contemplated for cancelling additive sinusoidal disturbances of a known frequency in OFDM receivers which arise e.g. from clock signals that are present for frequency reference, mixer control, and A/D converter control, as well as harmonics and mixing products of those periodic signals, coupling into some point in the receiver chain and appearing as rotating complex exponentials superimposed to complex baseband receive signals. According to the inventive method and apparatus an estimation of an amplitude and phase of a disturbing superimposed tone with a known frequency is obtained and the amplitude and phase estimation is used to cancel the spurious tone preventing a degradation of receiver sensitivity while achieving low implementation complexity.

Method and apparatus to cancel additive sinusoidal disturbances in OFDM receivers

A method is provided for processing received data symbols in an orthogonal frequency division multiplexing (OFDM) transmission scheme, and an OFDM baseband receiver which performs this method, in order to support frequency selective noise estimation, especially in interference limited environments, and to offer improved estimation performance and reduced computational complexity. This is achieved by determining time and frequency selective levels of combined noise and interference, computing noise normalization values for a respective time-frequency region of the time-frequency plane that applies in the transmission scheme employed, from the time and frequency selective noise plus interference levels, applying the noise normalization values to the received data symbols to obtain normalized data symbols, applying the noise normalization values to the channel estimates, to obtain normalized channel estimates, determining communication parameter estimates from the normalized channel estimates, and determining demodulated and decoded data from the normalized data symbols using the normalized channel estimates.

Method for processing received OFDM data symbols and OFDM baseband receiver

Synchronization tracking in an orthogonal frequency division multiplexing (OFDM) receiver by obtaining a DFT output vector; determining a sample timing offset indication using reference symbols extracted from the DFT output vector; and adapting the OFDM symbol timing using said determined indication. To provide an improved post-DFT algorithm for estimating time tracking error in OFDM receivers the determining includes (a) estimating the channel transfer function at equidistant frequency positions using said reference symbols, for a first OFDM symbol; determining plural frequency correlations for said equidistant frequency positions for said OFDM symbol; (c) repeating steps (a) and (b) for subsequent OFDM symbols; (d) linearly combining said plural frequency correlations for said plural OFDM symbols obtained in steps (a) through (c), for obtaining said sampling clock offset indication wherein the linear combining uses nonzero weights only. An OFDM receiver circuit arrangement performing this method.

Post DFT/FFT time tracking algorithm for OFDM receivers

A method of compensating interference of received symbols in a MIMO OFDM receiver employs MMSE equalization and LLR scaling, and a MIMO OFDM receiver includes a linear MMSE equalizer. The method provides a low-complexity, numerically robust method for compensating interference of received symbols and provides a low-cost, robust digital baseband receiver for MIMO-OFDM, achieved by merging linear MMSE equalization and scaling of the corresponding equalized symbols into a single algorithm that, for the 2&#xd7;M MIMO case, completely avoids computationally extensive matrix inversion and allows for significant simplification of symbol detection as compared to separate equalization and scaling.

Growing community of inventors

Dresden, Germany

Andreas Bury