Abstract: The present invention provides a method for enhancing accuracy of rate adaptation in a transmitter of a wireless communication system, which comprises setting a plurality of scores indicating reliabilities of a plurality of MCSs of the wireless communication system during rate adaption procedures of the plurality of MCSs, and adjusting the plurality of scores according to a plurality of response messages indicating receiving statuses of a plurality of transmitted packets.

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 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: A method for selecting modulation and coding scheme (MCS) for multi-antenna systems comprises the steps of: a multi-antenna system transmits signals according to MCSs of single spatial stream and determines an MCS accordingly. Subsequently, the multi-antenna system increases the number of the spatial streams applied, transmits signals according to the corresponding MCSs and determines an MCS accordingly until an optimum MCS is found.

Abstract: The module for switching between a long guard interval and a short guard interval comprises a signal processing unit, a measurement unit, a comparison unit and a switching unit. The module receives a first data symbol, and the data symbol has one of a long guard interval and a short guard interval. The signal processing unit is configured to generate a second data symbol in accordance with the first data symbol. The measurement unit is configured to measure a portion of the first and second data symbols in order to generate a first measurement value and a second measurement value. The comparison unit is configured to generate an output signal by comparing the first and second measurement values with a threshold value. The switching unit is configured to selectively switch guard intervals of subsequent data symbols in accordance with the output signal.

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 method for decoding LDPC code comprises the steps of: marking non-zero sub-matrices of a parity-check matrix of an LDPC code as 1 and zero sub-matrices of the parity-check matrix as 0 to form a simplified matrix; rearranging the sequence of rows of the simplified matrix according to the dependency between these rows; and updating the LDPC code in accordance with the sequence of the rows.

Abstract: A method for calibrating an analog circuit component comprises the steps of: generating a first signal with a baseband frequency; generating a second signal by processing the first signal via the analog component to be calibrated; generating a third signal by processing the second signal via a power amplifier, wherein the power amplifier operates in a nonlinear region; generating a fourth signal by processing the third signal via a low-pass filter; and defining the adjustment for the In-phase-Quadrature-phase imbalance (IQ imbalance) of the analog component and then re-executing the step of generating the first signal, if the fourth signal shows an IQ imbalance mismatch.

Abstract: A method for selecting a modulation and coding scheme (MCS) applied to a multiple-antenna system. The method calculates the throughout of a plurality of MCSs based on the signal to noise ratio of the multiple-antenna system and selects a MCS from the plurality of MCSs accordingly.

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.