摘要:
Provided are an apparatus for estimating a phase error and a phase error correcting system using the phase error estimating apparatus. The apparatus includes: a probability value estimating unit for estimating a negative log probability value for each transmission symbol by transforming a soft output information transferred from the outside to a log A posterior probability ratio (LAPPR) value; an APP value calculating unit for calculating a posterior probability (APP) value by applying a negative exponential function to the transmission symbol; an average value deciding unit for deciding an average value for each transmission symbol using the probability information entirely, partially, or selectively according to a probability information type; and a symbol phase estimating unit for estimating a phase of a symbol based on the decided average value.
摘要:
Provided is an apparatus for estimating phase offsets of multiple survival paths and a satellite communication system using the same. The apparatus includes: upper/lower decoding units for obtaining a phase offset estimation value and estimating phase offsets of each survival path based on a stored parameter estimation value of a previous state inputted from an external device; an interleaving/de-interleaving unit for minimizing correlation between data used to estimate a parameter according to the estimated phase offset value from the upper/lower decoding means; and a phase offset outputting unit for outputting the phase offset value estimated through the upper decoding unit and the de-interleaving unit.
摘要:
Provided are an apparatus for estimating a phase error and a phase error correcting system using the phase error estimating apparatus. The apparatus includes: a probability value estimating unit for estimating a negative log probability value for each transmission symbol by transforming a soft output information transferred from the outside to a log A posterior probability ratio (LAPPR) value; an APP value calculating unit for calculating a posterior probability (APP) value by applying a negative exponential function to the transmission symbol; an average value deciding unit for deciding an average value for each transmission symbol using the probability information entirely, partially, or selectively according to a probability information type; and a symbol phase estimating unit for estimating a phase of a symbol based on the decided average value.
摘要:
Provided is a method for estimating carrier wave or doppler frequency offset based on an approximated quadratic non-linear function in fine search, and a receiver employing the method. The method for estimating frequency offset includes the steps of: a) extracting more than three discrete samples in an order where the discrete samples are close to a maximum value of a power spectrum density function; b) inducing a quadratic non-linear function by using the extracted discrete samples; and c) estimating the frequency offset from a maximum point of the quadratic non-linear function. The technology of the present research makes it possible to exactly estimate frequency offset without increasing hardware complexity in estimation of carrier wave or doppler frequency offset.
摘要:
Provided is a method for estimating carrier wave or doppler frequency offset based on an approximated quadratic non-linear function in fine search, and a receiver employing the method. The method for estimating frequency offset includes the steps of: a) extracting more than three discrete samples in an order where the discrete samples are close to a maximum value of a power spectrum density function; b) inducing a quadratic non-linear function by using the extracted discrete samples; and c) estimating the frequency offset from a maximum point of the quadratic non-linear function. The technology of the present research makes it possible to exactly estimate frequency offset without increasing hardware complexity in estimation of carrier wave or doppler frequency offset.
摘要:
Disclosed herein is a demapping device and method for a Modified Dual Carrier Modulation (MDCM) system. The demapping device comprises: the received signal processing unit receives an MDCM signal preprocessed by an operation preparation unit, and calculates differences between squares of distances between the received signal and a plurality of constellation points; the index search unit searches for a constellation point closest to the received signal based on the differences between squares of distances between the received signal and each of a plurality of constellation points; and the demapping operation unit searches for constellation points close to the closest constellation point, and sends demapping result data to a decoding device. The demapping result is obtained by demapping based on differences between squares of distances between the closest constellation point and the close constellation points.
摘要:
There are disclosed a method of communicating for a smart utility network using a TV white space and an apparatus for the same. The method of communicating for a smart utility network using a TV white space according to the present invention includes: generating a time domain sequence repeated every predetermined number of samples; generating an OFDM symbol having a cyclic prefix length corresponding to an FFT size divided by a natural number of 2 or more and including samples of a number corresponding to the sum of the FFT size and the cyclic prefix length; and generating an SUN packet to be transmitted through a TV channel band selected in the TV white space by using the time domain sequence and the OFDM symbol. Accordingly, it is possible to satisfy all requirements required by the IEEE 802.15.4g SUN standardization group.