Abstract: To provide a quadrature modulator, a signal generating device, and a quadrature modulation method capable of correcting a gain balance error, a zero offset error, and an orthogonality error that occur during quadrature modulation. The quadrature modulator 20 includes a quadrature modulation unit 22, a quadrature modulation error calculating unit 40 that calculates quadrature modulation errors on the basis of the power of a quadrature-modulated signal output from the quadrature modulation unit 22, and an error correcting unit 30 that corrects a baseband signal such that the quadrature modulation errors are removed. The quadrature modulation error calculating unit 40 includes a power measuring unit 41 that measures the power of the quadrature-modulated signal, a gain balance error calculating unit 42, a zero offset error calculating unit 43, and an orthogonality error calculating unit 44.

Abstract: The present invention relates to an adaptive, high cost-performance efficient, and power-saving receiving method used for wireless communication systems, such as but not limited to Bluetooth (BT) system, in particular to a method which can detect the presence or absence of the adjacent channel interference (ACT) before the scheduled starting time for receiving a Bluetooth packet, and accordingly set the receiver configurations including the filter's pass-band bandwidth (BW), filter's order, the sampling rate or the number of analog-to-digital-converter (ADC) output bits, and the automatic-gain-control (AGC) algorithm to determine the low noise amplifier (LNA) and variable gain amplifier (VGA) settings.

Abstract: The present invention discloses a method for signal transmission and a user equipment (UE), wherein said method comprises: user equipment UE calculating an MSE of a first layer of signal and an MSE of a second layer of signal; the UE selecting a pre-coding matrix from a plurality of pre-coding matrices according to the sum of the MSE of the first layer of signal and the MSE of the second layer of signal; and the UE informing a base station to use the selected pre-coding matrix to transmit signals. By way of the present invention, the correct transmission of signals is ensured, the block error rate of the system is reduced, and the throughput of the system is improved.

Abstract: Embodiment methods and apparatus enable ATSC receiver devices to receive and process ATSC-M/H training sequences in order to improve the reception and decoding of an ATSC service. A processor within the ATSC receiver device may be configured to receive training sequences 1 and 2 of the ATSC-M/H signal. In an embodiment, the ATSC-M/H training sequence 2 may be received by correlating symbols of the two halves of the training sequence 2. If the result of correlating the symbols is greater than or equal to a threshold, the ATSC-M/H training sequence 2 may be received by the ATSC receiver and a counter for the training sequence 1 may start. The ATSC receiver may correlate two consecutive training sequences 1 to perform fine residual frequency error estimation.

Abstract: According to an aspect of the invention, a receiving apparatus includes a receiving unit, a reverse conversion unit, and an extracting unit. The receiving unit receives conversion data which is generated, based on a predetermined first rule, by converting transmission data including a plurality of bits and data including an error detection code for detecting an error of the transmission data. The reverse conversion unit reverse-converts, based on a predetermined second rule, the conversion data received by the receiving unit and reverse data generated by reversing a part of bits of the received conversion data to generate a plurality of reverse conversion data. The extracting unit extracts, from the plurality of the reverse conversion data, the reverse conversion data for which an error is not detected in an error detection based on the error detection code.

Abstract: The present invention relates to an adaptive, cost-performance efficient, power-saving apparatus for wireless communication systems, such as but not limited to Bluetooth (BT) receivers, and in particular to a packet-based receiver's decoding algorithm which can detect the presence or absence of the adjacent channel interference (ACI) before the scheduled starting time for receiving a Bluetooth packet, and accordingly set the receiver configurations including the filter's pass-band bandwidth (BW), filter's order, the sampling rate, the number of analog-to-digital-converter (ADC) output bits, and the automatic-gain-control (AGC) algorithm unit to determine the low noise amplifier (LNA) and variable gain amplifier (VGA) settings.

Abstract: A transmitter transmits a signal to a receiver using spread spectrum signals. The transmitter generates a respective signal. The transmitter separates the respective signal into multiple predefined portions, wherein each predefined portion is below a noise floor. The transmitter transmits at least a plurality of the predefined portions of the respective signal at discrete bandwidth intervals in accordance with a spread spectrum signal splitting technique. The discrete bandwidth intervals are portions of spectrum that are available for transmission. The receiver receives at least a plurality of the multiple predefined portions of the respective signal at the discrete bandwidth intervals. The receiver reconstructs the respective signal using at least a plurality of the predefined portions in accordance with the spread spectrum signal splitting technique.

Abstract: A method for multi-level data transmission includes encoding a data signal to be transmitted into N multi-level signals in accordance with an encoding table, where the data signal is characterized with a stream of binary data segments each of which has a data length of M bits, transmitting simultaneously the N multi-level signals through N data transmission channels, respectively; and decoding the N multi-level signals into the data signal by comparing each two of the N multi-level signals transmitted through the two data transmission channels to obtain a respective bit of the M bits of each binary data segment of the data signal based on comparison between the two corresponding multi-level signals.

Abstract: The present invention provides an aperiodic channel quality information sending method and a mobile terminal. The method comprises: a mobile terminal and network side pre-appointing one or more transmission modes which support the forming of dual flow beam, and aperiodic channel quality information CQI feedback mode(s) corresponding to the transmission modes; the network side indicating the mobile terminal with one pre-appointed transmission mode to be adopted, wherein when the mobile terminal receiving the indication of adopting the one pre-appointed transmission mode, the mobile terminal adopts the aperiodic CQI feedback mode corresponding to the one pre-appointed transmission mode to feed back the CQI information to the network side. The method of the present invention facilitates the reduction of signaling overhead and feedback overhead, the increase of the feedback dimensionality of the channel information, and the improvement of the throughput of the system.

Abstract: Attenuation is provided at the output of a power amplifier that provides transmitted signals or packets. The attenuation particularly provides separation of linear and non linear behavior of the signals. A reference packet is transmitted during attenuation. A normal packet is delivered without attenuation. Feedback from the reference packet can be extracted using the normal packet to calculate a loop-back response that is extracted and sent to a power amplifier pre-distortion correction algorithm.

Abstract: The present invention provides a method and an apparatus of controlling co-channel interference in a base station of a wireless communication system based on collaborative MIMO and the corresponding method and apparatus of assisting a serving base station to control co-channel interference in a mobile station of a wireless communication system based on collaborative MIMO. Since the feedback mechanism based on the codebook is employed in the collaborative MIMO system in the present invention to enable the BS to obtain the precoding information, the present invention can be used to the both TDD mode and FDD mode. Moreover, since the precoding vectors selected by the different mobile stations for a same BS are always orthogonal, multi-user co-channel interference can be reduced.

Abstract: A system for compensating for a Doppler frequency shift in communications between a mobile node and a fixed node. The system includes a Doppler frequency shift estimation unit configured to estimate the Doppler frequency shift experienced in a communication signal between the mobile node and the fixed node, wherein the Doppler frequency shift is estimated based on a location of the mobile node, a heading of the mobile node, and speed of the mobile node, and a location of the fixed node. The system also includes a frequency shift unit configured to shift a frequency of the communication signal in accordance with the estimated Doppler frequency shift.

Abstract: Methods for compensation of imbalance between I (In-phase) and Q (Quadrature) signal paths (12a, 12b, 605a, 605b) in a quadrature receiver (8) and a quadrature transmitter (600) are disclosed. In the receiver case, the imbalance is compensated for by means of post-distortion in the digital domain. In the transmitter case, the imbalance is compensated for by means of pre-distortion in the digital domain. The methods can be carried out with a relatively low computational complexity. Signal-processing devices (30, 610) for carrying out the methods are disclosed as well. The same basic internal structure may be used for the signal-processing device (30) in the receiver case as for the signal processing device (610) in the transmitter case.

Abstract: The present invention discloses an OFDM signal demodulation method and device thereof.

Abstract: Disclosed are an angle modulator, a transmission apparatus, and a radio communication apparatus that can compensate phase discontinuity when an operational mode of a voltage controlled oscillator is switched. Angle modulator (100) includes phase difference detection section (150) that detects a difference of phases between an input signal of subtractor (141) and an angle modulated signal, using the result of subtraction by subtractor (141) of frequency locked loop circuit (140); correction control section (160) that generates a control signal for compensating that difference of phases based on that difference of phases; correction section (120) that corrects the phase of the angle modulated signal by adding the control signal to an input signal of angle modulator (100), an input signal of loop filter (142), or an input signal of VCO (143) during a predetermined period after VCO (143) switches the operational mode (from time t3 to time t4).

Abstract: Methods and apparatus are provided for soft-decision maximum likelihood demodulation to decode a data vector transmitted in a multiple-input multiple-output (MIMO) communications channel. Soft-decision demodulators are disclosed that implement sphere decoding to reduce complexity of demodulation while preserving optimal performance. Candidate signal values associated with the transmitted data vector may be obtained and partitioned into signal bit groups. A sphere search may be performed over the candidate signal values within a search radius value to determine a smallest distance metric for each signal bit group. The search radius value may be updated based on a current smallest distance metric for each signal bit group. A log-likelihood ratio (LLR) may be computed from the determined smallest distance metrics for each signal bit group using a soft-decision demodulator.

Abstract: Various embodiments of a transmit diversity decoding techniques are provided. In one aspect, a method receives a first input that includes signals transmitted by M transmit antennas on C channels and received by N receive antennas, where M, N and C is each a positive integer greater than 1. The method also receives a second input that includes estimates of channel matrix elements. The method further generates an output that includes at least an estimate of a transmit signal transmitted by one of the M transmit antennas on one of the C channels based at least in part on the first and the second inputs.

Abstract: A demodulation method and a demodulator for an OFDM MIMO system are provided, and by using a received reference signal, the channel estimation value at the reference signal sub-carrier in each channel is obtained by estimation; by using the channel estimation value, an equalization matrix at the reference signal sub-carrier is obtained; by using the obtained equalization matrix to carry out the interpolation calculation, equalization matrixes are obtained; by using the data signals in various paths and corresponding equalization matrixes, an intermediate estimation value is obtained by calculation; by using a precoding matrix to carry out de-precoding on the intermediate estimation value, a final estimation value is obtained.

Abstract: A method and system for performing complex sampling of signals by using two or more sampling channels and for calculating time delays between these channels.

Abstract: A method includes receiving at a receiver a signal including reference symbols that is sent over a communication channel from a transmitter to the receiver. A response of the communication channel is estimated by applying one or more weighting values to the reference symbols. A noise correction factor is computed based on the weighting values. An estimate of a noise level in the received signal is computed based on the estimated response of the communication channel and the noise correction factor. The received signal is decoded based on the estimate of the noise level.