摘要:
A communication apparatus for a continuous phase modulation signal. The communication apparatus includes a first processing unit configured to generate first information of the continuous phase modulation signal using first symbol data; a symbol converting unit configured to convert the first symbol data into second symbol data or convert the second symbol data into the first symbol data; a symbol storage unit configured to store the second symbol data; a second processing unit configured to second information of the continuous phase modulation signal using the second symbol data stored in the symbol storage unit; a third processing unit configured to generate third information of the continuous phase modulation signal using a modulo operation of an integer related to a modulation index; and an output unit configured to add an output from the third processing unit and an output from the first processing unit and generate the continuous phase modulation signal.
摘要:
A communication apparatus for a continuous phase modulation signal. The communication apparatus includes a first processing unit configured to generate first information of the continuous phase modulation signal using first symbol data; a symbol converting unit configured to convert the first symbol data into second symbol data or convert the second symbol data into the first symbol data; a symbol storage unit configured to store the second symbol data; a second processing unit configured to second information of the continuous phase modulation signal using the second symbol data stored in the symbol storage unit; a third processing unit configured to generate third information of the continuous phase modulation signal using a modulo operation of an integer related to a modulation index; and an output unit configured to add an output from the third processing unit and an output from the first processing unit and generate the continuous phase modulation signal.
摘要:
A technology for modulating and demodulating a burst signal in a return link of a satellite system, in which the burst signal is modulated and transmitted from a transmission end of the return link and a symbol of the burst signal is identified and demodulated at a receiving end. The method includes estimating symbol timing of a burst received through the return link and synchronizing the estimated symbol timing of the burst to reference symbol timing; synchronizing a location of the timing-synchronized burst having the symbol timing synchronized to a location of a reference burst using a preamble symbol and a post-amble symbol of the timing-synchronized burst; and recovering a carrier of the location-synchronized burst whose location has been synchronized to the location of the reference burst using a pilot symbol of the location-synchronized burst.
摘要:
A technology for modulating and demodulating a burst signal in a return link of a satellite system, in which the burst signal is modulated and transmitted from a transmission end of the return link and a symbol of the burst signal is identified and demodulated at a receiving end. The method includes estimating symbol timing of a burst received through the return link and synchronizing the estimated symbol timing of the burst to reference symbol timing; synchronizing a location of the timing-synchronized burst having the symbol timing synchronized to a location of a reference burst using a preamble symbol and a post-amble symbol of the timing-synchronized burst; and recovering a carrier of the location-synchronized burst whose location has been synchronized to the location of the reference burst using a pilot symbol of the location-synchronized burst.
摘要:
Provided is a method for detecting frame sync and frame structure in a satellite broadcasting system, which acquires an estimated value for detecting frame structure and frame sync and overcomes distortion of correlation analysis values by summing differential correlation values for SOF positions in consideration of the variable frame length, and selecting a maximum value in a channel environment with low signal-to-noise ratio and high frequency error. SOF is a sync word indicating the start point of a frame. The method includes the steps of: acquiring SOF differential correlation value sequences; acquiring sums (di,t) of the correlation values normalized for SOF positions based on the number of symbols per frame by using the above-generated SOF differential correlation value sequences; and selecting a maximum value (dz,x) among the sums of correlation values, detecting z as a frame sync position, and detecting x as a frame structure index.
摘要:
Provided is a method for detecting frame sync and frame structure in a satellite broadcasting system. The method for detecting frame sync and frame structure includes the steps of: calculating differential correlation values of reception symbols; generating index sequences of reception symbols whose differential correlation values calculated above exceed a threshold value; calculating positions estimated as frame start points which correspond to a total frame number based on the number of symbols per frame for each frame structure; and detecting frame sync and frame structure based on the umber of positions where the above-calculated frame start point estimated positions and the above-generated index sequences are matched.
摘要:
Provided is a method for detecting frame sync and frame structure in a satellite broadcasting system. The method for detecting frame sync and frame structure includes the steps of: calculating differential correlation values of reception symbols; generating index sequences of reception symbols whose differential correlation values calculated above exceed a threshold value; calculating positions estimated as frame start points which correspond to a total frame number based on the number of symbols per frame for each frame structure; and detecting frame sync and frame structure based on the umber of positions where the above-calculated frame start point estimated positions and the above-generated index sequences are matched.
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:
An apparatus and method for acquiring reliable frame synchronization performance and frequency synchronization simultaneously in a communication system includes a differential correlator outputting a result value obtained by performing a differential operation based on an input signal having symbol timing synchronization and a value pre-defined with a sender sending the input signal, a frequency error calculator compensating for a frequency error based on the result value of the differential correlator and a frequency compensation control signal, and a frame synchronization determiner outputting the frequency compensation control signal if the result value of the differential correlator is greater than a threshold set having at least one value. By introducing a correlation scheme, i.e. Differential Generalized Post Detection Integration (DGPDI), in which differential information corresponding to a half of a symbol duration length is used within a duration from a frame start symbol to a UW symbol duration in a TDM/TDMA transmission structure in which a low SNR and a high frequency error must be considered, a more reliable frame synchronization estimation value can be acquired in comparison to a conventional frame synchronization scheme in which differential information between single neighbor symbols is used.
摘要:
Provided are an apparatus and method for deciding a transmission format using a variable frame length and a decoding method using the same. The apparatus for deciding the transmission format using the variable frame length includes: a frame synchronization acquiring unit for acquiring a frame synchronization of a received transmission frame; a correlation analyzing unit for performing a correlation analysis with respect to the transmission frame whose synchronization is acquired, considering frame lengths of respective frame structures; and a transmission frame structure deciding unit for deciding the structure of the received transmission frame using the analyzed correlation. Accordingly, a physical layer signaling code (PLSC) demodulation and decoding performance can be enhanced by determining the structure of the transmitted frame without carrying out a PLSC decoding in such a state that a frequency synchronization is not acquired.