摘要:
An ultra wideband network transmitter and receiver, and a method capable of switching to a high-speed mode or a low-speed mode are provided. The transmitter includes a multi-band orthogonal frequency division multiplexing (MB-OFDM) modem; a direct sequence code division multiple access (DS-CDMA) modem; a mode switch which switches to the MB-OFDM modem or the DS-CDMA modem according to a mode control signal; a phase lock loop (PLL) which locks a frequency used for MB-OFDM type modulation or the DS-CDMA type modulation; and a central processing unit (CPU) controls the PLL and mode switch. The receiver includes an MB-OFDM modem; an DS-CDMA modem; an automatic gain controller; an analog-to-digital converter; an PLL; a mode switch; and an CPU. The method includes receiving a command to transmit data; and switching to an MB-OFDM modem to select to a high-speed operation mode.
摘要:
A frequency generation apparatus and a method are provided. The frequency generation apparatus for generating a plurality of center frequencies for use in multi-band hopping communication, includes: an oscillator generating an oscillation frequency; a reference frequency generator multiplying the oscillation frequency by a first multiplication rate to generate a reference frequency; a compensation frequency generator multiplying the oscillation frequency by a second multiplication rate to generate a compensation frequency for compensating for the influence of a frequency offset of the oscillation frequency; and a center frequency generator generating the plurality of center frequencies using the reference frequency and the compensation frequency. Therefore, by compensating for the influence of a frequency offset of an oscillation frequency on the generation of center frequencies, it is possible to generate stable center frequencies.
摘要:
A DC offset correction apparatus and method of a receiver in a multiband-hopping communication system is provided. The DC offset correction apparatus of the receiver in the communication system which hops to a plurality of bands, includes a controller for generating and outputting a plurality of DC offset correction signals different from each other for the respective bands; a plurality of digital-to-analog converters (DACs) for receiving, digital-to-analog converting and outputting the plurality of the DC offset correction signals from the controller; an analog multiplexer (MUX) for switching to output one of the plurality of the DC offset correction signals output from the plurality of the DACs, respectively; and an adder for adding and outputting an input signal with the output signal of the analog MUX. Accordingly, the DC offset correction apparatus can be implemented by low-speed DACs and the fast analog MUX that are relatively small-sized and low-cost elements.
摘要:
A frequency generation apparatus and a method are provided. The frequency generation apparatus for generating a plurality of center frequencies for use in multi-band hopping communication, includes: an oscillator generating an oscillation frequency; a reference frequency generator multiplying the oscillation frequency by a first multiplication rate to generate a reference frequency; a compensation frequency generator multiplying the oscillation frequency by a second multiplication rate to generate a compensation frequency for compensating for the influence of a frequency offset of the oscillation frequency; and a center frequency generator generating the plurality of center frequencies using the reference frequency and the compensation frequency. Therefore, by compensating for the influence of a frequency offset of an oscillation frequency on the generation of center frequencies, it is possible to generate stable center frequencies.
摘要:
A DC offset correction apparatus and method of a receiver in a multiband-hopping communication system is provided. The DC offset correction apparatus of the receiver in the communication system which hops to a plurality of bands, includes a controller for generating and outputting a plurality of DC offset correction signals different from each other for the respective bands; a plurality of digital-to-analog converters (DACs) for receiving, digital-to-analog converting and outputting the plurality of the DC offset correction signals from the controller; an analog multiplexer (MUX) for switching to output one of the plurality of the DC offset correction signals output from the plurality of the DACs, respectively; and an adder for adding and outputting an input signal with the output signal of the analog MUX. Accordingly, the DC offset correction apparatus can be implemented by low-speed DACs and the fast analog MUX that are relatively small-sized and low-cost elements.
摘要:
A system, an apparatus and a method for transmitting/receiving data coded by a low density parity check matrix code are provided. The apparatus for transmitting data coded by a low density parity check code includes: a low density parity check encoder for encoding input data based on the low density parity check code; and a bit puncturer for puncturing columns in an order of columns which least degrade a performance caused by puncturing in the low density check code according to a code rate of an output data. Accordingly, the low density parity check code having superior performance can be implemented to the next generation mobile communication system supporting various code rates.
摘要:
A method is provided for reducing error occurring when a receiving end of a multiband OFDM system estimates original data from the received data. The multiband OFDM system, which transmits data using at last two radio resources, maps the data to at least two mapping data among a plurality of mapping data not to overlap each other and transmits the mapped data at least two times.
摘要:
A signal acquisition apparatus and method for reducing a false alarm rate are disclosed. The apparatus includes a comparator for detecting a first peak by comparing a correlation value of a received signal with a first threshold and detecting second peaks in a sample interval of the detected first peak based on a second threshold which is different from the first threshold. Thus, a signal is acquired based on a number of the detected second peaks. Accordingly, the false alarm rate due to the noise can be reduced while the detection probability is maintained even at a high SNR.
摘要:
A method for seamlessly receiving a symbol from a transmitting end at a receiving end even when error occurs in a certain radio resource of a multiband OFDM system that transmits a same symbol at least two times. The multiband OFDM system includes a transmitting end selecting two radio resources from at least three radio resources and consecutively transmitting a symbol using the selected radio resources, and a receiving end receiving the symbol from the transmitting end.
摘要:
A signal acquisition apparatus and method for reducing a false alarm rate are disclosed. The apparatus includes a comparator for detecting a first peak by comparing a correlation value of a received signal with a first threshold and detecting second peaks in a sample interval of the detected first peak based on a second threshold which is different from the first threshold. Thus, a signal is acquired based on a number of the detected second peaks. Accordingly, the false alarm rate due to the noise can be reduced while the detection probability is maintained even at a high SNR.