Abstract: The present document discloses a method for stopping iteration in an iterative Turbo decoder and an iterative Turbo decoder. Hard decisions from the two convolutional decoders of the iterative Turbo decoder are used simultaneously to determining when to stop the iteration in the iterative Turbo decoder.
Abstract: The present document discloses an apparatus for receiving Physical Uplink Control Channel (PUCCH) in Long Term Evolution (LTE) system, comprising: blocks of system FFT performing system FFT on data from a plurality of antennas, blocks of PUCCH RB processing units receiving the allocated logic resource index table and the local base sequence and output of the blocks of system FFT, and generating DMRS despread outputs and data values; a block of SR detection for receiving the data values and the DMRS despread outputs, and for generating SR detection results; blocks of user data extraction receiving data values and DMRS despread outputs, and performing user data extraction; blocks of PUCCH user processing units receiving an orthogonal sequence index, the data values and an output from blocks of user data extraction, and generating a ACK/NAK/CQI signal for a concerned UE.
Type:
Application
Filed:
July 9, 2010
Publication date:
July 11, 2013
Applicant:
ZTE WISTRON TELECOM AB
Inventors:
Aijun Cao, Jan Johansson, Xiaoming Su, Yujie Li
Abstract: An apparatus and method for linearizing a non-linear power amplifier. The method comprises: performing an iteration algorithm by using a desired output signal of the non-linear power amplifier, to calculate an input signal of the non-linear power amplifier, whereby with the calculated input signal of the non-linear power amplifier, the non-linear power amplifier is linearized. The apparatus and method can produce a signal on the output of the non-linear power amplifier with an arbitrarily high quality of performance.
Abstract: The present invention discloses method and system for improving performance of interference cancellation in a radio communication system. The method comprises: estimating power of an interfering signal contained in a received signal; estimating power of an additive estimate error signal added to the interfering signal; and canceling the interfering signal from the received signal if the estimated power of the additive estimate error signal is lower than the estimated power of the interfering signal. A cellular mobile terminal and a cellular base station comprising the system are also disclosed.
Abstract: Techniques for performing channel estimation in an orthogonal frequency domain multiplexing (OFDM) communications system include receiving a plurality of reference signals on a plurality of subcarriers, performing channel estimation to obtain a plurality of raw channel estimates based on the received plurality of reference signals, determining a number of raw channel estimates to be used for a channel estimate refinement and calculating a refined channel estimate using the number of raw channel estimates from the plurality of raw channel estimates.
Abstract: The disclosed methods and systems for improved OFDM channel estimation filtering take advantage of the presence of highly correlated adjacent subcarriers to reduce the computational intensiveness of channel estimation filtering. Specifically, baseband signals corresponding to a channel are received. The cyclic prefixes of the baseband signals are removed, and the resulting signal is transformed into the frequency domain, and compensated by a first time offset of the baseband receive signal. Subcarrier signals used to transmit the baseband signal are then extracted. Adjacent subcarriers having channel responses highly correlated to the subcarriers of the channel are identified, and the signal is compensated by a second time offset that corresponds to a minimal angle of the autocorrelation function of the subcarrier and adjacent subcarriers.
Abstract: An apparatus and method for linearizing a non-linear power amplifier. The method comprises: performing an iteration algorithm by using a desired output signal of the non-linear power amplifier, to calculate an input signal of the non-linear power amplifier, whereby with the calculated input signal of the non-linear power amplifier, the non-linear power amplifier is linearized. The apparatus and method can produce a signal on the output of the non-linear power amplifier with an arbitrarily high quality of performance.
Abstract: A digital predistortion circuit and method with extended operating range includes a predistortion function, a D/A converter, a multiplier for performing frequency translation and a power amplifier. The digital predistortion circuit includes a multiplier for receiving a signal to be transmitted and a gain correction factor, multiplying the gain correction factor with the signal to be transmitted, and outputting a result of the multiplication to the predistortion function, as well as a device for calculating the gain correction factor by using a predetermined reference gain and an estimated gain of the power amplifier, and outputting the calculated gain correction factor to the multiplier, whereby a gain of the power amplifier is quickly corrected. The digital predistortion circuit and the method thereof produce acceptable results for a more expanded range of TX power levels.
Abstract: An apparatus and method for compensating for transmit power losses that are caused by the addition of a clipping or crest factor reduction module in the TX path of a communications system. The method includes applying a gain to a signal input into the crest factor reduction module, so that a power of a signal output from the crest factor reduction module is equal to a power of a signal output from a baseband signal generation module in the TX chain. The apparatus and method have the benefit that the peaks of the signal to be transmitted will be consistent over a wide range of TX power values.