Qualcomm Incorporated

Maxim Gotman

Assaf Touboul

Tal Oved

Ziv Alina

Ronen Greenberger

Eran Richardson

Avner Dor

Meir Tsadik

Oren Matsrafi

Josef Waldman

Methods, systems, and devices are described for mitigating an unwanted increase in a coding rate of a wireless communication signal. A plurality of symbols including a transmitted codeword is received. The plurality of symbols including a first group of data symbols with a first modulation and coding scheme and a second group of data modulated pilot symbols with a second modulation and coding scheme. Applicable demodulation schemes are adaptively switched for each group of the plurality of symbols. The second group of data modulated pilot symbols are used in lieu of pilot symbols. The second modulation and coding scheme is a more reliable modulation and coding scheme than the first modulation and coding scheme.

Data-modulated pilots for phase and gain detectors

Methods, systems, and devices are described for calibrating a transmit path of a base station. A calibration symbol of a subframe may be generated for transmission on a downlink channel. The calibration symbol of the subframe may be transmitted. The calibration symbol may include a predefined waveform to calibrate the transmit path of the base station. At least part of the subframe including the calibration symbol may be received through a dedicated feedback receive path. The transmit path may be calibrated based at least in part on the received calibration symbol. The calibration symbols may replace one or more data symbols of the subframe. Control symbols may also be transmitted during the subframe. The control symbols may include reference signals and downlink control channels. The control symbols may signal to a mobile device a zero allocation of downlink resources during the subframe.

Calibration of a downlink transmit path of a base station

Methods, systems, and devices are described for mitigating phase noise. An output of a decoder is utilized to generate an estimation of a plurality of transmitted symbols. One or more phase errors of a plurality of received symbols are generated. The one or more phase errors are based at least in part on the estimation of the plurality of transmitted symbols. The one or more phase errors are generated by comparing angles between the plurality of received symbols and the estimation of the plurality of transmitted symbols. The output of the decoder used to generate the estimation is a plurality of a posteriori log-likelihood ratios (LLRs) of a plurality of transmitted bits. The estimation is generated by performing hard decision decoding on the output of the decoder and remodulating the hard decision decoding according to the modulation used by a transmitter on the plurality of transmitted bits.

Systems and methods to mitigate phase noise

Methods, systems, and devices are described for compensating for transmit I/Q impairments in a digital signal. A frequency domain version of a first one of the components may be scaled at a wireless modem according to a frequency dependent I/Q impairment compensation function to obtain a compensated frequency domain version of the first one of the components. The compensated frequency domain version of the first one of the components may be combined with a frequency domain version of a second one of the components at the wireless modem to produce a compensated frequency domain version of the digital signal. The compensated frequency domain version of the digital signal may be transformed to the time domain at the wireless modem to produce a compensated time domain version of the digital signal.

Frequency dependent I/Q impairment compensation

Methods, systems, and apparatuses are described for compensating for impairments of a wireless device. In accordance with a disclosed method, a set of equalizer taps for an analog pipeline of the wireless device is determined. A first set of complex filter taps and a second set of complex filter taps are also determined, by modifying the set of equalizer taps according to an estimated imbalance of the analog pipeline of the wireless device. A signal associated with the analog pipeline is processed with a complex filter according to the first set of complex filter taps and the second set of complex filter taps. The processing provides a combined imbalance compensation and equalization of the signal. The complex filter may include a first complex half-filter associated with the first set of complex filter taps and a second complex half-filter associated with the second set of complex filter taps.

Combined imbalance compensation and equalization of a signal

A method for soft remodulation in a receiver of transmissions over a wireless telecommunication system, the method including obtaining from a FEC decoder a-posteriori LLR values, converting the a-posteriori LLR values into bit probabilities and computing improved soft symbols estimates as expected values using the bit probabilities in a recursive algorithm. Preferably, the step of converting is implemented using a pre-computed Look Up Table (LUT). Preferably, the step of computing is implemented in a Multiplier-Accumulator having a SIMD structure.

Method for soft modulation in a wireless telecommunication network

A method and device for reducing Peak-to-Average Power Ratio (PAPR) of a transmitted signal in a wireless telecommunication system utilizing CFR technique, the method including performing peak-windowed clipping of a transmitted signal using at least two cascaded clipping stages and individually configuring parameters for each clipping stage before performing the peak-windowed clipping.

Method and apparatus for crest factor reduction in telecommunications systems

A receiver and method for HARQ combining of a received codeword in a receiver with a FEC decoder, the method including computing Log Likelihood Ratios (LLRs) of demodulated soft symbols of the received codeword and outputting the LLRs as a-priori soft bits; performing iterative decoding of the a-priori soft bits in a Forward Error Correction (FEC) decoder; outputting a posteriori soft bits of the a priori soft bits of the received codeword from the FEC decoder; and HARQ combining the a posteriori soft bits with a retransmission of the received codeword.

Method and system for HARQ combining in a telecommunication system

A method and system for processing LLRs, in a receiver, of transmissions over a wireless telecommunication system, the method including receiving multiple soft symbols, selecting a set of appropriate instructions for LLR calculation for the soft symbols, arranging the soft symbols in a register of a processor according to the selected instructions, selecting an appropriate single instruction from the set of instructions to be implemented by the processor using the soft symbols in the register as operands, and calculating, by a computation unit, multiple LLR values for the multiple soft symbols, in parallel, by means of the selected instruction.

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Kfar-Saba, Israel

Maxim Gotman