Abstract: A method, for determining a first amount of a plurality of high-throughput long training fields within a packet in a wireless communication system, includes determining a second amount of a plurality of space time streams needed by the wireless communication system transmitting the packet, and setting the first amount to be greater than or equal to 8 when the second amount is greater than 4.

Abstract: A method for generating training sequences in a transmitter having a plurality of transmitting antennas, includes dividing each of a plurality of symbols into a plurality of sub-symbols with a quantity equal to a quantity of the plurality of transmitting antennas, sequentially transforming a plurality of sub-symbols corresponding to same positions in each of the plurality of symbols, to generate a plurality of training data, and generating a plurality of training sequences of independent frequencies according to the plurality of training data, for forming parts of packets emitted by the plurality of transmitting antennas.

Abstract: A method of generating a preamble sequence includes generating a first frequency-domain preamble sequence according to information of the packet, the first frequency-domain preamble sequence comprising a plurality of subsequences corresponding to a plurality of sub-channels, adjusting a phase of each subsequence of the first frequency-domain preamble sequence, for generating a second frequency-domain preamble sequence, transforming the second frequency-domain preamble sequence into a first time-domain preamble sequence, performing a cyclic shift delaying process on the first time-domain preamble sequence, for generating a plurality of delayed time-domain preamble sequences, and normalizing power of the plurality of delayed time-domain preamble sequences, for generating a second time-domain preamble sequence that is a preamble sequence of the packet.

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 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.

Abstract: A method of enhancing accuracy of position estimation for a wireless communication system includes receiving a plurality of input measurements required for estimating a position of a target, and generating a plurality of Gaussian probability density functions corresponding to the plurality of input measurements, the plurality of Gaussian probability density functions being used for estimating the position of the target.

Abstract: A method for determining a position of a mobile station in a wireless communication system includes generating a state equation set according to a current state of the mobile station, for predicting a position and a velocity of the mobile station after a predetermined period, and corresponding the state equation set to a graphic interface for calculating the position and the velocity after the predetermined period.

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 present invention provides a method for simplifying a probabilistic rate adaptation procedure in a wireless communication system, which comprises calculating a conditional probability density function of SNR of a transmitted signal by the probabilistic rate adaptation procedure, to generate an SNR estimation result, taking logarithm on the SNR estimation result to generate a logarithm result, and partitioning SNR values into a plurality of regions according to the logarithm result, to generate a discrete function from the SNR estimation result.

Abstract: A method for determining a modulation and coding scheme for signals with packets of different lengths comprises the steps of: grouping signals according to their packet lengths, wherein each group has a weighting for each modulation and coding scheme; transmitting signals with different modulation and coding schemes; adjusting weights of each modulation and coding scheme of each group according to the quality of receiving the transmitted signals; determining a modulation and coding scheme according to the weightings of each modulation and coding scheme in the group corresponding to the packet length of the signal to be transmitted.

Abstract: A method of examining the eligibility of a modulation and coding scheme includes determining a range of pseudo signal-to-noise ratio (pseudo-SNR) corresponding to a range of packet correct rate (PCR) acceptable for a transmitter, obtaining a first score of a positive acknowledgement (ACK) and a second score of a negative acknowledgement (NACK) according to the range of pseudo-SNR and the range of PCR, applying weighting to a score of a response message, which is one of an ACK message and a NACK message, and a pseudo-SNR corresponding to an immediately preceding response message when receiving the response message, for generating a pseudo-SNR corresponding to the response message, and examining the eligibility of a modulation and coding scheme in use according to the pseudo-SNR corresponding to the response message.

Abstract: A method for adjusting a modulation and coding scheme based on signal quality comprises the steps of: determining a reference modulation and coding scheme based on signal reception qualities of transmitted signals according to a plurality of modulation and coding schemes; determining a temporary modulation and coding scheme according to a modulation and coding scheme selection method; determining a final modulation and coding scheme according to a first table and the differences between the reference modulation and coding scheme and the temporary modulation and coding scheme.

Abstract: A method for determining a modulation and coding scheme comprises the steps of: transmitting signals with different modulation and coding schemes and adjusting weighting of each modulation and coding scheme based on the quality of transmitted signals on a receiving end; adjusting the weighting of each modulation and coding scheme based on suggested modulation and coding schemes; determining a modulation and coding scheme to use according to the weighting of each modulation and coding scheme.

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: 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 decomposing a barrel shifter decomposes N, the number of digits of input word, into N1 to Nm, and utilizes m layers of shifter circuit layer, which are composed of a plurality of barrel shifters, such that each barrel shifter performs a shifting procedure to obtain the desired output word.

Abstract: Considering both performance and cost of an iterative receiver, the present invention provides an iterative signal receiving method for a wireless communications system. The iterative signal receiving method includes utilizing a channel estimating (CE) process to perform channel estimation for a received signal according to first log-likelihood ratio (LLR) data to generate second LLR data, and then generating the first LLR data according to an error correction code (ECC) decoding process and the second LLR data. When the ECC decoding process is a convolutional decoding process, the CE process is a zero-forcing process, a minimum mean square error (MMSE) process or an interpolation-based process. When the ECC decoding process is a low density parity check code (LDPC) decoding process, the CE process is a maximum likelihood (ML) process or a maximum a posteriori (MAP) process.

Abstract: A method that selects an error-correction code for use in a multiple-input multiple output (MIMO) wireless communication system is disclosed that optimizes the performance of the MIMO wireless communication system. The method selects the error-correction code according to at least one system parameter and at least one channel parameter of the MIMO wireless communication system, such that the selected error-correction code matches the hardware configuration and channel setting of the MIMO wireless communication system.