摘要:
Disclosed is a multi-channel signal receiver technology. An RF front-end in an RF receiver receiving at least two RF signals with different transmission bandwidths includes: at least two RF tuners receiving, amplifying, and frequency-converting the at least two RF signals, respectively; a switch selecting one of signals output from the at least two RF tuners; a channel filter eliminating interference signals included in a signal output from the switch, and passing a signal of a transmission band; an ADC converting the signal output from the channel filter into a digital signal; a fixed sampling frequency generator generating and transferring a fixed sampling frequency to the ADC.In the RF front-end, by processing filtering and sampling of signals with a narrow transmission bandwidth through a residual calculation capacity of a digital processor a construction of an RF front-end may be simplified and manufacturing costs may be reduced.
摘要:
Disclosed is a multi-channel signal receiver technology. An RF front-end in an RF receiver receiving at least two RF signals with different transmission bandwidths includes: at least two RF tuners receiving, amplifying, and frequency-converting the at least two RF signals, respectively; a switch selecting one of signals output from the at least two RF tuners; a channel filter eliminating interference signals included in a signal output from the switch, and passing a signal of a transmission band; an ADC converting the signal output from the channel filter into a digital signal; a fixed sampling frequency generator generating and transferring a fixed sampling frequency to the ADC.In the RF front-end, by processing filtering and sampling of signals with a narrow transmission bandwidth through a residual calculation capacity of a digital processor a construction of an RF front-end may be simplified and manufacturing costs may be reduced.
摘要:
There is provided a method for effectively estimating transmission modes and lengths of guard intervals in the implementation of an integrated services digital broadcasting-T (ISDB-T) receiver. A method for estimating transmission modes and lengths of guard intervals in a broadcasting system having signals transmitted therein, the signals having a plurality of transmission modes, the transmission modes each having plural kinds of transmission symbols, the transmission symbols in each of the transmission modes having the same length of data intervals and different lengths of guard intervals, the transmission symbols in different transmission modes having different lengths of data intervals and different lengths of guard intervals, the guard interval in each of transmission symbols being obtained by copying a rear section of the data interval in each of the symbols and prefixing the copied rear section to a front section of the data interval, and one of the transmission symbols being periodically repeated, the method comprising: performing correlation while scanning the signals using a plurality of correlation windows respectively corresponding to the plurality of transmission modes; selecting the transmission mode corresponding to the correlation window having an outputted correlation result among the plurality of correlation windows as a transmission mode of a received signal; and estimating a existing time of the correlation result as the length of a guard interval in the received signal.
摘要:
Disclosed are an apparatus and a method for preventing data read error for OFDM symbol demodulation. An average time synchronization offset estimating unit estimates average time synchronization offset between a pilot symbol of a time synchronized data frame and pilot symbols of data frames next to the time synchronized data frame. A data buffer control unit acquires a start location of a data frame to be read using the estimated average time synchronization offset, and controls reading of written data frames using the acquired start location information of the data frame to be read. In the apparatus and the method, a data buffering using a ring buffer construction may compensate time synchronization offset of samples containing real data in an OFDM symbol and prevent an erroneous read error in order to improve a receiving performance of a receiver.
摘要:
There are provided an apparatus for synchronizing an OFDM signal using an open-loop frequency synchronization method, which can estimate and compensate for various types of frequency errors generated in a frequency modulation broadcasting/communication system to which the open-loop frequency synchronization method is applied, and a frequency offset estimation scheme using the apparatus. To this end, the apparatus for synchronizing an OFDM signal using the open-loop frequency synchronization method comprises a time offset estimator, a time offset compensator, a fractional frequency offset estimator, an integer frequency offset estimator, a frequency offset controller and a frequency offset compensator. Accordingly, in the OFDM demodulation broadcasting/communication system using the open-loop frequency synchronization method, a frequency offset, which is generated due to the carrier frequency difference between a transmitter and a receiver, a frequency shift generated due to the mobile environment of a receiver, the temperature characteristic of a local oscillator, and the like, can be estimated and compensated.
摘要:
There is provided an apparatus for receiving a T-DMB signal. The apparatus for receiving a T-DMB signal comprises an input buffer receiving and buffering a T-DMB signal comprising a null symbol and a phase reference symbol (PRS); an initial synchronizing unit estimating and compensating for time and frequency offsets of the T-DMB signal using the null symbol and the PRS; a frame tracking unit performing estimation of the time offset and measurement of a strength of an output signal from the input buffer; an OFDM signal demodulating unit performing I/Q demodulation, frequency compensation, OFDM demodulation and de-interleaving with respect to an output signal of the frame tracking unit; a channel decoding unit performing channel decoding with respect to an output signal of the OFDM signal demodulating unit and checking quality of the channel-decoded signal; and a controller controlling operations of the initial synchronizing unit, the OFDM signal demodulating unit and the channel decoding unit 308 based on the strength of the signal measured by the frame tracking unit and the quality of the signal checked by the channel decoding unit. Accordingly, unnecessary calculating processes arc reduced by measuring the strength and quality of an input signal, thereby maximizing power efficiency of the apparatus.
摘要:
Disclosed are an apparatus and a method for preventing data read error for OFDM symbol demodulation. An average time synchronization offset estimating unit estimates average time synchronization offset between a pilot symbol of a time synchronized data frame and pilot symbols of data frames next to the time synchronized data frame. A data buffer control unit acquires a start location of a data frame to be read using the estimated average time synchronization offset, and controls reading of written data frames using the acquired start location information of the data frame to be read. In the apparatus and the method, a data buffering using a ring buffer construction may compensate time synchronization offset of samples containing real data in an OFDM symbol and prevent an erroneous read error in order to improve a receiving performance of a receiver.
摘要:
There are provided an apparatus for synchronizing an OFDM signal using an open-loop frequency synchronization method, which can estimate and compensate for various types of frequency errors generated in a frequency modulation broadcasting/communication system to which the open-loop frequency synchronization method is applied, and a frequency offset estimation scheme using the apparatus. To this end, the apparatus for synchronizing an OFDM signal using the open-loop frequency synchronization method comprises a time offset estimator, a time offset compensator, a fractional frequency offset estimator, an integer frequency offset estimator, a frequency offset controller and a frequency offset compensator. Accordingly, in the OFDM demodulation broadcasting/communication system using the open-loop frequency synchronization method, a frequency offset, which is generated due to the carrier frequency difference between a transmitter and a receiver, a frequency shift generated due to the mobile environment of a receiver, the temperature characteristic of a local oscillator, and the like, can be estimated and compensated.
摘要:
There is provided an apparatus for receiving a T-DMB signal. The apparatus for receiving a T-DMB signal comprises an input buffer receiving and buffering a T-DMB signal comprising a null symbol and a phase reference symbol (PRS); an initial synchronizing unit estimating and compensating for time and frequency offsets of the T-DMB signal using the null symbol and the PRS; a frame tracking unit performing estimation of the time offset and measurement of a strength of an output signal from the input buffer; an OFDM signal demodulating unit performing I/Q demodulation, frequency compensation, OFDM demodulation and de-interleaving with respect to an output signal of the frame tracking unit; a channel decoding unit performing channel decoding with respect to an output signal of the OFDM signal demodulating unit and checking quality of the channel-decoded signal; and a controller controlling operations of the initial synchronizing unit, the OFDM signal demodulating unit and the channel decoding unit 308 based on the strength of the signal measured by the frame tracking unit and the quality of the signal checked by the channel decoding unit. Accordingly, unnecessary calculating processes arc reduced by measuring the strength and quality of an input signal, thereby maximizing power efficiency of the apparatus.