摘要:
An encoder using LDPC (low density parity check) codes, and an encoding method. The encoder comprises a parity check matrix generator for generating a parity check matrix H; and a codeword generator for processing the parity check matrix H to generate a codeword, and the codeword generator comprises: an AB analyzer for analyzing the parity check matrix H into matrixes A and B; a pivoting unit for pivoting the parity check matrix H; a bit-reversing unit for bit-reversing the pivoted matrix; an LU analyzer for analyzing the matrix A into matrixes L and U; and a codeword generator unit for performing a logical operation on the matrixes A, B, L and U. A bit-reversing method is used to effectively generate a parity check matrix having a high girth by using a regular encoder.
摘要:
An encoder using LDPC (low density parity check) codes, and an encoding method. The encoder comprises a parity check matrix generator for generating a parity check matrix H; and a codeword generator for processing the parity check matrix H to generate a codeword, and the codeword generator comprises: an AB analyzer for analyzing the parity check matrix H into matrixes A and B; a pivoting unit for pivoting the parity check matrix H; a bit-reversing unit for bit-reversing the pivoted matrix; an LU analyzer for analyzing the matrix A into matrixes L and U; and a codeword generator unit for performing a logical operation on the matrixes A, B, L and U. A bit-reversing method is used to effectively generate a parity check matrix having a high girth by using a regular encoder.
摘要:
Disclosed is an automatic gain control device in an orthogonal frequency division multiplexing system. A variable gain amplifier controls a gain of an input signal; an energy calculator calculates an energy of the input signal; a truncator accumulates the calculated energies, finds an average thereof, and generates a DC offset of the input signal; a subtracter subtracts a predefined reference value from the DC offset, and outputs a signal; and an RC filter feeds the value output by the subtracter back to the variable gain amplifier so that the value output by the subtracter may be used for an automatic gain control. The predefined reference value given to be 4.Ov is a reference power generated based on a saturation to RMS ratio for minimizing the bit error rate of the orthogonal frequency division multiplexing system.
摘要:
The present invention relates to a method for automatic gain control (AGC) before an initial synchronization of a mobile station modem in OFDM system, and an apparatus thereof The AGC apparatus includes: an initial synchronization inspector that verifies whether an initial synchronization for an input block sample (k) signal has been performed; a frame divider that divides a frame into predetermined intervals B(k) for the input block sample(k) signal in the case that the initial synchronization has not been performed; a reference value inspector that compares a difference value Pref−Pcalc, between a predetermined reference value Pref and sample data average energy Pcalc, with a predetermined value; a count controller that increases or decreases the count when the difference value Pref−Pcalc compared by the reference value inspector is greater or less than the predetermined value; a count inspector that inspects whether the count is greater or less than 0 when the input block sample (k) reaches a maximum value MAX; and a gain controller which increases or decreases the gain, level by level, according to the count inspection result of the count inspector.
摘要:
In a signal monitoring apparatus of a base station of a communication system having multiple antennas, a transmitting/receiving unit transmits a plurality of transmit signals by using the multiple antennas or processes a plurality of receive signals received through the multiple antennas. A radio frequency calibration unit calibrates the transmit signals transmitted through the multiple antennas, and processes at least one target transmit signal among the plurality of transmit signals so as to monitor the at least one target transmit signal. A signal monitoring unit receives at least one first signal or at least one second signal, and transmits the at least one first signal or the at least one second signal to user equipment. The at least one first signal is a signal processed from at least one target receive signal among the plurality of receive signals, and the at least one second signal is a signal processed from the at least one target transmit signal by controlling the radio frequency calibration unit.
摘要:
An apparatus and method for canceling a DC offset efficiently removes the DC offset by calculating the DC offset after acquiring synchronization in a terminal receiver used for an orthogonal frequency division multiplexing system. The apparatus for canceling the DC offset includes an adding/averaging unit (130), an accumulator (140), a synchronization determiner (150), and a pulse density modulation signal generator (160). The adding and averaging the added input data signals over one frame. The accumulator (140) outputs a DC offset control value by successively accumulating the DX offsets calculated from the adding and averaging unit. The synchronization determiner (150) determines whether to output the DC offset control value provided by the accumulator (140) based on synchronization information. The pulse density modulation signal generator (160) generates a digital pulse density modulation signal based on a representative value provided by the synchronization determiner (150).
摘要:
In a calibration apparatus in a communication system, a modulation unit calculates a reference signal by modulating a downlink signal, and a digital Intermediate Frequency (IF) unit converts the reference signal to an intermediate frequency signal. An up-converter converts the intermediate frequency signal to a Radio Frequency (RF) signal, and a down-converter generates a received signal for each of the paths from the RF signal to be transmitted through each path. A calibrator calculates a correction value for each path and a delay value by using the reference signal and the received signal for each path.
摘要:
The present invention relates to a method for automatic gain control (AGC) before an initial synchronization of a mobile station modem in OFDM system, and an apparatus thereof. The AGC apparatus includes: an initial synchronization inspector that verifies whether an initial synchronization for an input block sample (k) signal has been performed; a frame divider that divides a frame into predetermined intervals B(k) for the input block sample(k) signal in the case that the initial synchronization has not been performed; a reference value inspector that compares a difference value Pref−Pcalc, between a predetermined reference value Pref and sample data average energy Pcalc, with a predetermined value; a count controller that increases or decreases the count when the difference value Pref−Pcalc compared by the reference value inspector is greater or less than the predetermined value; a count inspector that inspects whether the count is greater or less than 0 when the input block sample (k) reaches a maximum value MAX; and a gain controller which increases or decreases the gain, level by level, according to the count inspection result of the count inspector.
摘要:
An apparatus and method for canceling a DC offset efficiently removes the DC offset by calculating the DC offset after acquiring synchronization in a terminal receiver used for an orthogonal frequency division multiplexing system. The apparatus for canceling the DC offset includes an adding/averaging unit (130), an accumulator (140), a synchronization determiner (150), and a pulse density modulation signal generator (160). The adding and averaging the added input data signals over one frame. The accumulator (140) outputs a DC offset control value by successively accumulating the DX offsets calculated from the adding and averaging unit. The synchronization determiner (150) determines whether to output the DC offset control value provided by the accumulator (140) based on synchronization information. The pulse density modulation signal generator (160) generates a digital pulse density modulation signal based on a representative value provided by the synchronization determiner (150).
摘要:
In a signal monitoring apparatus of a base station of a communication system having multiple antennas, a transmitting/receiving unit transmits a plurality of transmit signals by using the multiple antennas or processes a plurality of receive signals received through the multiple antennas. A radio frequency calibration unit calibrates the transmit signals transmitted through the multiple antennas, and processes at least one target transmit signal among the plurality of transmit signals so as to monitor the at least one target transmit signal. A signal monitoring unit receives at least one first signal or at least one second signal, and transmits the at least one first signal or the at least one second signal to user equipment. The at least one first signal is a signal processed from at least one target receive signal among the plurality of receive signals, and the at least one second signal is a signal processed from the at least one target transmit signal by controlling the radio frequency calibration unit.