Abstract: A radio communication device includes an amplification unit configured to amplify a transmission signal, an antenna transmitting an amplification signal amplified by the amplification unit, a detection unit configured to detect a reflection signal that is the amplification signal reflected from a side of the antenna, and a correction processing unit configured to correct the transmission signal, wherein the correction processing unit is configured to correct the transmission signal based on the reflection signal when installation of a filter through which the amplification signal passes is recognized.

Abstract: A symbol-timing recovery function of a receiver is provided with a signal combiner (465) coupled to a first receive branch with a first receive signal (10) and to a second receive branch with a second receive signal (20). The signal combiner (465) generates a combined signal (C) on the basis of the first receive signal (10) and the second receive signal (20). Further, a common timing error detector (470C) is provided. The common timing error detector (470C) is coupled to the signal combiner (465) and is configured to generate a common timing error signal (TEC) on the basis of the combined signal. A first digital symbol timing for the first receive signal (10) and a second digital symbol timing for the second receive signal (20) are recovered on the basis of the common timing error signal (TEC).

Abstract: A method of feedforward phase recovery on a data stream is described. Phase estimation base points are calculated, at a phase detector, for each block of the received data stream. A current phase, at a phase interpolator, between two phase estimation base points. Data stream delays within the phase detector are matched with delays within the phase interpolator.

Abstract: A terminal and a communication method thereof whereby, even in a case of employing the asymmetric carrier aggregation system and further employing the MIMO transmission method for upstream channels, the error characteristic of control information can be prevented from being degraded. In the terminal (200), a transport signal forming unit (212) forms transport signals by arranging, based on a arrangement rule, ACK/NACK and CQI in a plurality of layers. According to the arrangement rule, an error detection result is arranged, on a priority basis, in a layer that is different from a layer in which the channel quality information is arranged. In this way, the puncturing of CQI using ACK/NACK can be minimized, with the result that the error characteristic of control information can be prevented from being degraded.

Abstract: The present invention relates to a method for transmitting, by a base station, a downlink signal using a plurality of transmission antennas comprises the steps of: applying a precoding matrix indicated by the PMI, received from a terminal, in a codebook to a plurality of layers, and transmitting the precoded signal to the terminal through a plurality of transmission antennas. Among precoding matrices included in the codebook, a precoding matrix for even number transmission layers can be a 2×2 matrix containing four matrices (W1s), the matrix (W1) having rows of a number of transmission antennas and columns of half the number of transmission layers, the first and second columns of the first row in the 2×2 matrix being multiplied by 1, the first column of the second row being multiplied by coefficient “a” of a phase, and the first column of the second row being multiplied by “?a”.

Abstract: A communication system and method for extending coverage of a base transceiver station. The communication system includes processing circuitry that receives a communication signal over a wireless channel. The received communication signal is processed through an adaptable equalizer to reduce noise, distortion, interference, and frequency errors. In another aspect of the invention, a frequency of a reference signal in the communication system is adjusted to compensate for frequency errors between the communication system and the source of the communication signal. The equalized and frequency adjusted communication signal is then retransmitted into an extended coverage area. Wireless coverage is thereby provided between a base transceiver station and a mobile device in the extended coverage area.

Abstract: A distortion compensation device which reduces a distortion of an amplifier which is added to an output signal of the amplifier, the distortion compensation device including: a plurality of distortion compensation coefficient storage circuits which stores a plurality of distortion compensation coefficients and outputs the distortion compensation coefficients according to an amplitude of an input signal of the amplifier, a distortion compensating processing circuit which adds the distortion compensation coefficient output from each of the plurality of distortion compensation coefficient storage circuits to the input signal of the amplifier, and a distortion compensation coefficient updating circuit which performs weighting processing on the distortion compensation coefficient output from each of the plurality of distortion compensation coefficient storage circuits to reduce the distortion compensation coefficient and which calculates an update value of the distortion compensation coefficient by using the disto

Abstract: In a method of selecting a codebook for precoding a wireless transmission signal, a characteristic of a wireless communication channel is measured, and a codebook size is selected using (i) an expected throughput for each of a plurality of different codebook sizes given the measured characteristic of the wireless communication channel, and (ii) channel overhead associated with each of the plurality of different codebook sizes. Based on matrix selection criteria, a best matrix is selected from a codebook of the selected codebook size, and an indicator of the selected matrix is transmitted.

Abstract: The method includes receiving a data signal, the data signal including two training sequences, performing a first evaluation of the data signal based on a first training sequence of the two training sequences, performing a second evaluation of the data signal based on a second training sequence of the two training sequences, and processing the data signal based on a result of the first and second evaluations.

Abstract: Adaptive filtering is used to substantially cancel distortion in radio frequency (RF) signals. Such adaptive filtering can be used in an RF transmitting device to pre-compensate an RF signal with compensation (inverse) distortion to cancel inherent transmission path distortion from the RF signal. Adaptive filtering can also be used in a multi-carrier RF receiving device to cancel from a given carrier signal distortion due to cross talk from adjacent carrier signals. Adaptive filtering in an RF transceiver can be used to cancel from a received RF signal distortion arising from leakage of a transmit signal into the receive path.

Abstract: A circuit may include a phase difference selector, a clock signal generator, a reference clock phase detector, and a data signal phase detector. The phase difference selector may be configured to select one of multiple reference clock phase difference signals generated by the reference clock phase detector based on a difference in phase between multiple clock signals and a reference clock. The clock signal generator may be configured to generate the multiple clock signals based on the selected reference clock phase difference signal. The data signal phase detector may be configured to generate a data phase difference signal based on differences in phase between the clock signals and a data signal. The data phase difference signal may be used by the phase difference selector to select one of the reference clock phase difference signals.

Abstract: A receiver is provided that is configured to estimate the symbol constellation of a signal modulated using a quaternary symbol constellation where data is transmitted to two mobile stations multiplexed on a shared channel comprising two branches, where the branches correspond to the real and imaginary parts of one complex-valued baseband signal. The receiver is configured to demodulate the modulated signal using the training sequences from both sub-channels.

Abstract: The assembly includes a first sub-assembly with, on a transmitter side, a modem having a plurality of inputs, an output for a total data stream, and signal paths connected in parallel. Each signal path includes a modulation stage, a stage for sampling modulated signals and a mixer stage Outputs of mixer stages are connected to inputs of a summation stage, and output of the summation stage is connected to output of the modem. A second sub-assembly has an input for initialization data connected to an assembly for controlling a test operation. The sub-assembly is connected to a downstream carrier management assembly having a plurality of outputs. Each output is connected to a test sequence generating unit. Outputs of all test sequence generating units are connected to a parallel/serial converter assembly connected downstream of a filter assembly. Output of the filter assembly is connected to output of the second sub-assembly.

Abstract: Modulated signal A is transmitted from a first antenna, and modulated signal B is transmitted from a second antenna. As modulated signal B, modulated symbols S2(i) and S2(i+1) obtained from different data are transmitted at time i and time i+1 respectively. In contrast, as modulated signal A, modulated symbols S1(i) and S1(i)? obtained by changing the signal point arrangement of the same data are transmitted at time i and time i+1 respectively. As a result the reception quality can be changed intentionally at time i and time i+1, and therefore using the demodulation result of modulated signal A of a time when the reception quality is good enables both modulated signals A and B to be demodulated with good error rate performances.

Abstract: A mobile wireless communications device may include an antenna, and a receiver coupled to the antenna and being configured to use a modulation having memory for a received message in a block structure. The block structure may include a pair of mini-probes and a body therebetween. The receiver may be configured to demodulate the received message by determining a corresponding set of received signal characteristic values based upon the pair of mini-probes, and determining a decode starting point in the body based upon the set of received signal characteristic values. The receiver may be configured to demodulate the received message by at least, from the decode starting point, decoding the body in a first time direction, and decoding the body in a second time direction based upon a result of the decoding in the first direction.

Abstract: A frequency-domain interpolator for estimating a plurality of channels corresponding to a plurality of subcarriers comprises an edge pilot estimation unit, for generating a plurality of pilots according to a plurality of input pilots, a pilot interval ratio and a complexity parameter; a first selection unit, for selecting a plurality of pilot groups from the plurality of pilots according to the pilot interval ratio and the complexity parameter; a second selection unit, for generating a plurality of coefficient groups corresponding to the plurality of channels according to a channel profile and a used pilot interval, wherein each of the plurality of coefficient groups corresponds to a set of the plurality of channels; and a filter unit, for generating the plurality of channels according the plurality of pilot groups, the plurality of coefficient groups, and a relation between the plurality of pilot groups and the plurality of coefficient groups.

Abstract: A cognitive radio signal processing method suitable for single receiver devices where interference is mitigated using projection of received multi-dimensional signal space to maximize SNR by orthogonalizing interference is described. The method is based on a well-known LMS solution that is computed from received multi antenna and multicarrier signals in a novel way. This method solves the requirement of multiple RF chains in low cost handsets by introducing a protocol synchronous antenna switcher that allows, for example, a LTE handset with a single antenna to benefit from algorithms that typically require multiple receivers for the same frequency, i.e. MIMO.

Abstract: A folding adaptive equalizer is provided. The equalizer comprises an equalizer core and an automatic gain control loop. The equalizing transfer function of the equalizer core is modulated by one or more gain control signals generated by the automatic gain control loop and by a folding signal generated by the automatic gain control loop. When the folding signal is inactive, an increase in the gain control signals produces an increase in the high-frequency, high-bandwidth gain of the transfer function of the equalizer core. When the folding signal is active, further gain can be applied by decreasing the gain control signals, which produces a frequency-shift in the transfer function of the equalizer core toward lower bandwidth and an increase in the high-frequency, low-bandwidth gain of the transfer function of the equalizer core.

Abstract: A mechanism for jointly correcting carrier phase and carrier frequency errors in a demodulated signal. A computer system may receive samples of a baseband input signal (resulting from QAM demodulation). The computer system may compute values of a cost function J over a grid in a 2D angle-frequency space. A cost function value J(?,?) is computed for each point (?,?) in the grid by (a) applying a phase adjustment of angle ? and a frequency adjustment of frequency ? to the input signal; (b) performing one or more iterations of the K-means algorithm on the samples of the adjusted signal; (c) generated a sum on each K-means cluster; and (d) adding the sums. The point (?e, ?e) in the 2D angle-frequency space that minimizes the cost function J serves an estimate for the carrier phase error and carrier frequency error. The estimated errors may be used to correct the input signal.

Abstract: Embodiments of this disclosure include methods in which spurs generated by the drifting of an oscillation frequency of an oscillation signal provided by a free-running oscillator may be minimized and/or eliminated from an output signal of a phase locked loop (PLL). Methods include adjusting the free-running oscillator to prevent the oscillation frequency from drifting so that the spurs are eliminated. Performance data generated when the communications device engages a communications channel that is known not to generate spurs is compared to performance data generated when the communications device engages a desired communications channel. The free-running oscillator is adjusted until the two types of performance data are matched. Other methods include adjusting the dithering module of the PLL to prevent the oscillation frequency from drifting so that the spurs are eliminated.