摘要:
Provided is a method for adjusting Fast Fourier Transform (FFT) window positioning in a Multi Band Orthogonal Frequency Division Multiplexing Ultra-Wideband (MB-OFDM UWB) system. The method includes the steps of acquiring an initial FFT window position and a frequency hopping position, demodulating a received signal by using the initial FFT window position and the frequency hopping position acquired in the acquiring step, transmitting received data information to a Media Access Control (MAC) layer with a reception frame (RX frame) structure and judging at the MAC layer whether or not a packet error is occurred based on Frame Check Sequences (FCSs), and if no packet error is occurred, returning to the demodulating step, and if the packet error is occurred, changing a register map by using a predetermined interface line in a MAC-physical layer (MAC-PHY) interface to thereby adjust the FFT window position and the frequency hopping position, and then returning to the demodulating step.
摘要:
A parallel equalizer for a DS-CDMA UWB system and method thereof are provided. The parallel equalizer includes: a filter block for filtering a training input signal in a ‘training mode’, and filtering the plurality of input signals in parallel in a ‘symbol decision mode’; a symbol decision block for obtaining a symbol error based on a output from the filter block and a training symbol in the ‘training mode’, and estimating a transmission symbol for each of the input signals in the ‘symbol decision mode’, obtaining an error of one among the estimated transmission symbols for a symbol error calculating input signal; and an weight update block for updating a filter tap coefficients of the filter block based on the training input signal or the symbol error calculating input signal and the symbol error and transmitting the updated filter tap coefficients into the filter block.
摘要:
Provided is an apparatus and method for detecting a time-frequency code in an MB-OFDM UWB system. The apparatus includes a controller for providing a band selection signal to the RF receiver and outputting a preamble selection signal at regular symbol periods to calculate a cross correlation value for a predetermined time period more than a beacon frame interval when a time-frequency code search start signal is received; and a cross correlator for storing information on preamble patterns, selecting a preamble stored depending on the preamble selection signal, and calculating a cross correlation value for a digital signal transferred through the RF receiver, wherein the controller determines a time-frequency code using a preamble where a peak occurs as a time-frequency code that is currently in use when a peak signal is inputted based on the calculated cross correlation value, and transmits the determined time-frequency code to the MAC receiver.
摘要:
Provided are an apparatus and method for estimating and correcting a frequency offset in a multiband-Orthogonal Frequency Division Multiplexing Ultra-Wideband system using a time frequency hopping. The method includes the steps of: calculating a tangent input having a first value (X) and a second value (Y) by using PS symbols transferred over same frequency band with respect to one of a plurality of frequency bands used for frequency hopping; calculating tan(X/Y) using the first value (X) and the second value (Y), and calculating an index corresponding to the value of tan(X/Y) from a look-up table created by reflecting a relative frequency offset with respect to a center frequency; calculating indexes representing frequency offsets estimated with respect to remaining frequency bands used for frequency hopping from the look-up table by using the calculated index; extracting an index of a numerical controlled oscillator according to correction positions with respect to a plurality of frequency bands by using the calculated indexes; and correcting the frequency offsets estimated using the extracted indexes according to time frequency patterns by using a numerical controlled oscillator table.
摘要:
Provided are an apparatus and method for estimating and correcting a frequency offset in a multiband-Orthogonal Frequency Division Multiplexing Ultra-Wideband system using a time frequency hopping. The method includes the steps of: calculating a tangent input having a first value (X) and a second value (Y) by using PS symbols transferred over same frequency band with respect to one of a plurality of frequency bands used for frequency hopping; calculating tan(X/Y) using the first value (X) and the second value (Y), and calculating an index corresponding to the value of tan(X/Y) from a look-up table created by reflecting a relative frequency offset with respect to a center frequency; calculating indexes representing frequency offsets estimated with respect to remaining frequency bands used for frequency hopping from the look-up table by using the calculated index; extracting an index of a numerical controlled oscillator according to correction positions with respect to a plurality of frequency bands by using the calculated indexes; and correcting the frequency offsets estimated using the extracted indexes according to time frequency patterns by using a numerical controlled oscillator table.
摘要:
A rake receiver for DS-CDMA UWB system and a DS-CDMA receiver having the same are provided. The rake receiver includes: a channel estimator for estimating a channel having a predetermined chip duration by using a synchronization acquisition sequence; a tracking module for detecting a channel variation and adjusting a synchronization position value when the channel variation is detected; a first switch for selecting one of an output value of an analog-to-digital converter and an output value of a correlator and outputting the selected value; a second switch for selecting one of the output value of the analog-to-digital converter and the output value of the correlator; and a plurality of demodulators having a parallel processing structure to demodulate received signals by using the channel estimation value inputted from the channel estimator, the synchronization position value stored by the tracking module, and an output value of the second switch.
摘要:
Provided is a method for adjusting Fast Fourier Transform (FFT) window positioning in a Multi Band Orthogonal Frequency Division Multiplexing Ultra-Wideband (MB-OFDM UWB) system. The method includes the steps of acquiring an initial FFT window position and a frequency hopping position, demodulating a received signal by using the initial FFT window position and the frequency hopping position acquired in the acquiring step, transmitting received data information to a Media Access Control (MAC) layer with a reception frame (RX frame) structure and judging at the MAC layer whether or not a packet error is occurred based on Frame Check Sequences (FCSs), and if no packet error is occurred, returning to the demodulating step, and if the packet error is occurred, changing a register map by using a predetermined interface line in a MAC-physical layer (MAC-PHY) interface to thereby adjust the FFT window position and the frequency hopping position, and then returning to the demodulating step.
摘要:
A parallel equalizer for a DS-CDMA UWB system and method thereof are provided. The parallel equalizer includes: a filter block for filtering a training input signal in a ‘training mode’, and filtering the plurality of input signals in parallel in a ‘symbol decision mode’; a symbol decision block for obtaining a symbol error based on a output from the filter block and a training symbol in the ‘training mode’, and estimating a transmission symbol for each of the input signals in the ‘symbol decision mode’, obtaining an error of one among the estimated transmission symbols for a symbol error calculating input signal; and an weight update block for updating a filter tap coefficients of the filter block based on the training input signal or the symbol error calculating input signal and the symbol error and transmitting the updated filter tap coefficients into the filter block.
摘要:
Provided are a high speed and low power fixed-point multiplier and method thereof. The multiplier includes: a partial product calculation unit for dividing input data into a plurality of bit groups, each bit group having a predetermined number of bits, generating partial products by independently multiplying a fixed coefficient for each bit group, and summing partial products included in a corresponding bit group, to thereby generate a summed partial products; and an adding unit for adding the summed partial products of each bit group generated from the partial product calculation unit.
摘要:
Provided are a high speed and low power fixed-point multiplier and method thereof. The multiplier includes: a partial product calculation unit for dividing input data into a plurality of bit groups, each bit group having a predetermined number of bits, generating partial products by independently multiplying a fixed coefficient for each bit group, and summing partial products included in a corresponding bit group, to thereby generate a summed partial products; and an adding unit for adding the summed partial products of each bit group generated from the partial product calculation unit.