Abstract: A data fusion based safety surveillances system has a first through Nth virtual monitoring systems and a data fusion and decision device. The data fusion and decision device defines an ith detection model of the ith virtual monitoring system, and estimates an ith detection loss probability of the ith virtual monitoring system according to detection loss sample numbers of batches of ith monitored data of the ith virtual monitoring system under conditions corresponding to the locations, batches of context data and existence of intruder, the ith detection model, the batches of ith monitored data corresponding to locations of the ith virtual monitoring system and the batches of context data. The data fusion and decision device determines a fusion parameter set according to the first through Nth detection loss probabilities, and performs data fusion on a first through Nth detection results to generate a decision result.

Abstract: A data fusion based safety surveillances system has a first through Nth virtual monitoring systems and a data fusion and decision device. The data fusion and decision device defines an ith detection model of the ith virtual monitoring system, and estimates an ith detection loss probability of the ith virtual monitoring system according to detection loss sample numbers of batches of ith monitored data of the ith virtual monitoring system under conditions corresponding to the locations, batches of context data and existence of intruder, the ith detection model, the batches of ith monitored data corresponding to locations of the ith virtual monitoring system and the batches of context data. The data fusion and decision device determines a fusion parameter set according to the first through Nth detection loss probabilities, and performs data fusion on a first through Nth detection results to generate a decision result.

Abstract: A signal transmitting apparatus for orthogonal frequency division multiplexing (OFDM) system comprises a compandor, a predistortor, a power amplifier and a feedback module. The compandor is configured to compress and expand a transmitted signal. The predistortor is configured to perform a predistortion operation on output signals of the compandor. The power amplifier is configured to amplify output signals of the predistortor. The feedback module is configured to adjust parameters of the compandor and the predistortor based on a feedback signal.

Abstract: Disclosed is a method and apparatus for dynamic channel assignment (DCA) in a wireless network, which describes the complex channel assignment problem with a decoding problem. The invention describes the decoding problem with a normal graph and specifies all the local rules enforced by all the nodes at access point sides and subscriber sides. Then, the invention carries out the sum-product algorithm to solve the DCA. It is not only a fully-distributed low-complexity DCA technology, but also significantly increases the network throughput. The invention further adopts the concept of subscriber exclusive region to guarantee the link quality between a subscriber and an access point.

Abstract: A method and related system of transmission channel detection condition in a wireless communication system are disclosed. The method includes receiving a symbol, performing a channel estimation operation to generate a channel estimation result according to the symbol, performing a cross correlation operation on the channel estimation result and an initial channel estimation result to generate an operation result, and determining whether the condition of the transmission channel have changed or not.

Abstract: The method for beamforming in a wireless communication system comprises the steps of: receiving a sounding packet so as to estimate channel state information between a transmitter and a receiver; generating a beamforming matrix in accordance with the channel state information; generating a beamforming steering matrix by multiplying the beamforming matrix by a rotation matrix; and feeding back the beamforming steering matrix.

Abstract: A method for detecting radar signals comprises the steps of: receiving signals detected by a master device; receiving signals detected by a slave device; detecting radar pulses from the signals received by the master device; detecting radar pulses from the signals received by the slave device; and determining radar signals by combining the radar pulses detected by the master device and slave device.

Abstract: The present invention discloses a signal processing device and a signal processing method. The signal processing device includes a plurality of receiving devices, a storage module, a weighting module, and a processing module. Each of the receiving devices is capable of receiving an original signal stream, thus the plurality of receiving devices can generate a set of signal streams. The storage module is used for storing a plurality set of signal streams generated by the plurality of receiving devices. The weighting module can generate plurality sets of rotated signal streams according to a reference phase and the plurality sets of signal streams, and further generate a set of weighting signal according to the rotated signal streams. And, the processing module can generate a set of weighting signal streams according to the set of weighting signal and the plurality set of signal streams.

Abstract: An approximation method for SNR soft information for a transmitter of a communications system includes obtaining a conditional probability density function (PDF) corresponding to a response message of a transmitted packet, obtaining a PDF of a probability distribution model, and a mean and a variance of the PDF, by approximating the conditional PDF corresponding to the response message with the probability distribution model, and calculating a second mean and a second variance of a second PDF approximated to a conditional PDF of SNR corresponding to the transmitted packet according to the mean and the variance of the PDF, and a first mean and a first variance of a first PDF approximated to a conditional PDF of SNR corresponding to another transmitted packet immediately preceding the transmitted packet.

Abstract: A rate adaptation method comprises the steps of: updating the probability density function of the SNR of a transmitted signal according to the receiving status of the transmitted signal and the probability density function before update; and updating the transmission rate of the transmitted signal according the updated probability density function.

Abstract: A RF transceiver includes an antenna, a receiver, a baseband circuit, a transmitter, and a T/R switch circuit. The T/R switch circuit is used for coupling the antenna and the receiver or coupling the antenna and the transmitter. The T/R switch circuit is coupled to the baseband circuit so as to receive biases provided from the baseband circuit. The T/R switch circuit includes four transistors and a power detector. The power detector detects the power of the output signal of the T/R switch circuit, so that the baseband circuit can adjust biases provided to the T/R switch circuit according to the power of the output signal.

Abstract: A method for detecting radar signal comprises the steps of: receiving a signal by a receiver, wherein the strength of the received signal is controlled within a range; sampling the received signal so as to obtain a plurality of sampling values; dividing the sampling values into a plurality of segments; summing up the absolute values of the sampling values in each segment; and determining that the received signal includes radar signals if at least one summation is greater than a threshold.

Abstract: An echo cancellation circuit for an RFID reader and the method thereof are provided. The echo cancellation circuit includes a gain calculator, a gain adjustment circuit, and a subtraction circuit. The gain calculator provides a complex gain value according to a carrier signal and a received signal through an adaptive algorithm. The gain adjustment circuit is coupled to the gain calculator. The gain adjustment circuit multiplies the carrier signal by the complex gain value, and outputs the result of the multiplication. The subtraction circuit is coupled to the gain adjustment circuit. The subtraction circuit subtracts the output of the gain adjustment circuit from the received signal, and then provides the result of the subtraction as the output signal of the echo cancellation circuit.

Abstract: A method for detecting radar signal comprises the steps of: sampling a received signal so as to obtain a plurality of sampling values; taking an absolute value of the sampling values so as to obtain at least two parameters; and determining whether the received signal includes radar signals in accordance with the at least two parameters.

Abstract: A method sub-carrier grouping for a wireless communication system including a plurality of sub-carriers is disclosed. The method includes determining a coherent bandwidth of the plurality of sub-carriers, and dividing the plurality of sub-carriers into a plurality of sub-carrier groups according to the coherent bandwidth, wherein the size of each sub-carrier group is smaller than or equal to the coherent bandwidth.

Abstract: A base station selection method is disclosed. The wireless communication system includes a plurality of base stations with overlapped radio ranges and a plurality of wireless devices. The method includes steps of modeling the plurality of base stations as a plurality of variable nodes in a factor graph, modeling the plurality of wireless devices as a plurality of constraint nodes in the factor graph, and selecting a base station for transmission from the plurality of base stations based on the factor graph. Each variable node is defined as a frequency band state of a corresponding base station. Each constraint node is linked to the variable nodes corresponding to the base stations that include the corresponding wireless device in their radio ranges, and is defined as that the frequency band states of the base stations including the corresponding wireless device in their radio ranges can not be all turned off.

Abstract: A calibration device for a power amplifier includes a calculation unit, a first storage unit and a multiplier. The calculation unit is utilized for generating a calibration factor according to a value of a characteristic parameter of the power amplifier. The first storage unit coupled to the calculation unit, for storing the calibration factor. The multiplier is coupled to the first storage unit and a baseband unit, for multiplying a baseband signal outputted from the baseband unit by the calibration factor for generating an input signal to the power amplifier.

Abstract: A frequency band assignment method for a wireless communication system is disclosed. The wireless communication system includes a plurality of base stations. The plurality of base stations has overlapped radio ranges and forms a plurality of independent overlapping areas. The method includes steps of modeling the plurality of base stations as a plurality of variable nodes in a factor graph, modeling the plurality of independent overlapping areas as a plurality of constraint nodes in the factor graph, and using the factor graph to perform frequency assignment for the plurality of base stations. Each variable node is defined as a frequency band to be assigned to the modeled base station. Each constraint node is defined as that the frequency bands assigned to the base stations forming the modeled overlapping area cannot be equivalent.

Abstract: A simulation method for a wireless communication system with multiple antennas and multiple nodes is disclosed. The method adopts a separable correlation channel model to simulate a wireless communication system with multiple antennas and multiple nodes, wherein in this model the nodes in the same area are correlated, and the nodes in different areas are not correlated.

Abstract: A method of estimating a position of a target device for a wireless communication system includes receiving a plurality of received signal strength measurements with respect to a plurality of base stations measured by the target device when the target device enters an area, and applying a graphical model to estimate the position of the target device according to the plurality of received signal strength measurements.