Abstract: Adaptive low complexity minimum mean square error (MMSE) channel estimator for OFDM systems operating over mobile channel. Complexity of the estimator is reduced by partitioning sub-carriers into windows where, window size is optimized by considering channel model mismatch error (MME). Three types of adaptive windowed MMSE (W-MMSE) estimators include: A first type, a simplified delay profile applied as channel reference model, and optimum window size adaptive to the estimated signal-to-noise ratio. A second type, a group of candidate channel reference models are considered. The receiver roughly estimates and selects current reference model from candidate group, then adapts optimum window size based on the estimated SNR and selected channel model. A third type, the current channel statistics are finely estimated and window size is iteratively optimized at receiver.

Abstract: A private branch exchange system capable of enabling radio communication terminals belonging to an extension group to perform device-to-device direct communication (D2D communication) by using a radio access network such as LTE. A private branch exchange server 300 includes a transition trigger detection unit 310 configured to detect a trigger for a transition to the direct communication, an extension group list retention unit 320 configured to retain an extension group list containing an identifier of the radio communication terminal belonging to the extension group, a subgroup selection unit 330 configured to select a certain subgroup from the extension group list, and a direct communication command unit 340 configured to send permission information on the direct communication and configuration information on a communication environment necessary for the direct communication to the radio communication terminal contained in the subgroup selected by the subgroup selection unit 330.

Abstract: A method is provided for limiting noise in a plurality of signals received in a multiple input receiver. The method includes a processing operation for decorrelating of the noise present in the signals received.

Abstract: A method for trigger information transmission and protocol conversion is provides, and the method includes: an MTC-IWF which has received trigger information about an MTC device acquires routing information of the MTC device through a subscribed serving network element, the MTC-IWF transmits received trigger information about the MTC device to a serving core network node of the MTC device through an SMS core network node; the serving core network node of the MTC device transmits the trigger information to the MTC device; in the above process, the MTC-IWF or a dedicated IWF or an SMS router implements signaling conversion between an MAP protocol and a Diameter protocol. A system for trigger information transmission and protocol conversion is also provided for implementing above method. It is possible using the method and system to transmit trigger information through a T4 interface and establish a process of converting between an MAP protocol and a Diameter protocol.

Abstract: A delay quantity estimation apparatus comprises a first correlation value arithmetic unit to calculate a first correlation value as a correlation value between a first input signal and a feedback signal delayed with a first delay value; a second correlation value arithmetic unit to calculate a second correlation value as a correlation value between the first input signal and a feedback signal delayed with a second delay value; and a delay quantity estimation unit to estimate a delay quantity of the feedback signal with respect to the input signal on the basis of the first difference value as a difference between the first correlation value and the second correlation value, wherein the second delay value is a value given by adding a certain value to the first delay value.

Abstract: A method and apparatus for sampling a high bandwidth analog signal includes: splitting the high bandwidth analog signal into N parallel channels; randomly demodulating each of the signals; sampling each demodulated signal using a sub-Nyquist sampling rate; combining each sampled signal into a sub-Nyquist signal; compressive sensing the combined sub-Nyquist signal to estimate missing samples of a full Nyquist rate uniform sample set X(n); convolving X(n) with N analysis filters, each analysis filter having a different coefficient; decimating output of each analysis filter using decimation ratios of M:1 to generate a sub-banded signal set Yi (n), i=1, . . . , N; processing the sub-banded signal set; up-sampling each processed sub-band signal by M; convolving each up-sampled sub-band signal with a corresponding synthesis filter; and combining two or more of the convolved signals to generate a non-uniform spectral partitioning of the high bandwidth analog signal.

Abstract: Disclosed are a double-stream beamforming method and device, which relate to communication technology. The method comprises: first, according to a DOA angle, determining an array response vector; then according to the array response vector, in accordance with the number of each group of transmission antennae of a base station, distributing parameters to generate two groups of coefficients, and according to the two groups of coefficients, conducting beamforming on the antennae. There is no need to conduct characteristic value decomposition to obtain a characteristic vector, thereby reducing the double-stream beamforming complexity.

Abstract: The mixer of a transmit chain of a wireless transmitter (such as the transmitter of a cellular telephone handset) is driven with low third harmonic in-phase (I) and quadrature (Q) signals. The low third harmonic I and Q signals have three or more signal levels, and transition between the these three or more signal levels at times such that each of the I and Q signals approximates a sine wave and has minimal third harmonic spectral components. In one example, reducing the third harmonic components of the I and Q signals simplifies design of amplifier stages of the transmitter and helps reduce receive band noise.

Abstract: Techniques are disclosed for turbo decoding orthogonal frequency division multiplexing OFDM symbols. Techniques for combined turbo decoding and equalization are disclosed. The disclosed techniques can be implemented in receivers that receive wired or wireless OFDM signals and produce data and control bits by decoding the received signals.

Abstract: An equalizer includes a first discrimination circuit to receive an input signal corresponding to a signal output from a transmit-side equalizer to binarize the input signal by a first threshold value in unit time, a second discrimination circuit to binarize the input signal by a second threshold value in unit time, a first delay circuit to delay an output signal of the first discrimination circuit and that includes N-number (N>=2) of stages of unit delay circuits connected in cascade and operating in unit time, a second delay circuit to receives an output signal of the second discrimination circuit and that includes not less than an (N+1)-number of stages of unit delay circuits connected in cascade and operating in unit time, and a control unit that receives an output of the first delay circuit, and a second output signal output from the second delay circuit.

Abstract: A reception device including: an antenna configured to receive a radio signal including a radio frame that includes a plurality of symbols, and a processor configured to perform a first processing for estimating a first interference noise power for one or more first specified symbols of the plurality of symbols, each of the one or more first specified symbols including each of one or more reference signals respectively, and to perform a second processing for estimating a second interference noise power for one or more second specified symbols of the plurality of symbols, each of the one or more second specified symbols including no reference signal, the second interference noise power differing from the first interference noise power.

Abstract: A novel and useful apparatus for and method of packet detection and carrier frequency offset estimation. The packet detection mechanism is robust to channels and sustains reasonable miss-detect (and false alarm) rates at low SNR values. The mechanism uses a modified combined cross correlation and delay and correlate scheme. A delay and correlate scheme is used in order to handle the effects of multipath while swapping integration and multiplication to increase cross-correlation factors resulting in improved sensitivity in low SNR conditions. Correlation is divided into multiple chains to generate a plurality of partial correlations to observe short patterns in the spread sequence resulting in improved performance in long multipath channels.

Abstract: A method of encoding video data using soft decision quantization makes use of iterative encoding to provide the ability to optimize encoding across different functional elements in a hybrid video encoder. Iterative encoding is used to allow quantization step size, motion prediction and quantization levels to be optimized despite their interrelated nature.

Abstract: In a method for channel adaptation, an analog input signal is received with a bimodal receiver via a communications channel. The analog input signal is converted to a digital input signal with an analog-to-digital converter of a digital receiver of the bimodal receiver. Channel coefficients are detected for the digital input signal associated with the communications channel. The channel coefficients indicate a number of post-cursor taps of the bimodal receiver to be used to provide an equalized digital output signal from the digital input signal. It is determined whether the number of post-cursor taps or a value associated therewith is equal to or less than a threshold number. A switch from the receiving of the analog input signal by the digital receiver to an analog receiver of the bimodal receiver is made to provide the equalized digital output signal for the analog input signal.

Abstract: A digital filter receives a sequence of input signal values. A filtering block performs a filtering operation on sequence of input signal values that is controlled by filter coefficients. A control block also receives the sequence of input signal values. The control block evaluates detected changes over time with respect to the sequence of input signal values and selects values for the filter coefficients based on the detected changes. The detected change over time provides an indication of the whether the sequence of input signal values is changing signal state. If so, the filter coefficients are selected to emphasize signal response time over signal noise filtering for the filtering operation. Otherwise, the filter coefficients are selected to emphasize signal noise filtering over signal response time for the filtering operation.

Abstract: A transport stream (TS) generating apparatus, a transmitting apparatus, a receiving apparatus, a digital broadcast system having the above, and a method thereof are provided. The digital broadcast system includes a transport stream (TS) generating apparatus which generates a multi transport stream (TS) by multiplexing a normal stream and a turbo stream having a variable coding rate, a transmitting apparatus which re-constructs the multi TS by processing the turbo stream, and transmits the re-constructed multi TS, and a receiving apparatus which receives the re-constructed multi TS, and decodes the normal stream and the turbo stream respectively, to recover normal data and turbo data. Accordingly, a multi TS, which includes normal stream and a turbo stream of various coding rates, can be transmitted and received efficiently.

Abstract: A hybrid platform for a software defined radio (SDR) includes a receive/transmit antenna, a radio frequency (RF) frontend, a baseband processor, and a SDR positioned along a signal path that couples the antenna, the RF frontend, and the baseband processor. The SDR includes a transmit processing chain, a receive processing chain, and a FPGA that includes control logic to reduce distortion caused by signal transmission within the SDR.

Abstract: A wireless communications device may include a receiver configured to receive a continuous phase modulation (CPM) signal and a demodulator coupled downstream from the receiver. The demodulator may be configured to generate a CPM correlation matrix based upon an expected CPM signal, and generate a temporary correlation matrix. The temporary correlation matrix may include a first copy of the CPM correlation matrix inverted in time, and a second copy of the CPM correlation matrix.

Abstract: The present disclosure provides an interference avoidance method of a pulse signal. According to the method, before the pulse signal is transmitted, the pulse signal is split into two parallel pulse sub-signals which can be synthesized using a subtraction synthesis method and thus restored to the pulse signal. In this way, in the parallel transmissions of the two parallel pulse sub-signals, interferences from which the two sub-signals suffer are identical to each other. Thus, after the two parallel pulse sub-signals are synthesized using the subtraction synthesis method, the interference signals offset each other to allow the synthesized pulse signal to carry no interference signals, which effectively avoids false control caused by the interference signals carried in the transmission of the pulse signal and simultaneously avoids the false control caused by an attenuation or a distortion of the pulse signal due to the traditional filtering method.

Abstract: One or more aspects of the disclosure provide an efficient equalization scheme capable of mitigating multi-path interference on channels with large delay spread using short-length equalizers. That is, by dividing stored samples of a signal received on the multi-path channel by time into a plurality of clusters, a short-length equalizer can be utilized in an iterative fashion on each of the clusters, thus eliminating the need for a large length equalizer while still providing improved performance over that of a Rake receiver at large delay spreads. Other aspects, embodiments, and features are also claimed and described.