摘要:
The present invention relates to an apparatus and a method for receiving signal for extent of timing synchronization in MB-OFDM UWB System. The invention divides the digital samples completed of sampling twice as much as minimum sampling clock required to restore the MB-OFDM received signal into ODD data path and EVEN data path, executes the packet detection and timing synchronization for each of divided path and selects the data of path with larger cross correlation value at the timing synchronization point to secure the stable receiving performance in system environment with severe frequency offset and prevent the FTT window shift within preamble section through adding minimum hardware and structural change without increasing the system clock.
摘要:
It is possible to intuitively determine whether to control transmission power of a current data transmission rate mode or to change the data transmission rate mode by extracting an automatic gain controller (AGC) index after driving algorithm of an AGC, recognizing a channel clear assessment (CCA) status by using the extracted AGC index, and generating link quality indicator (LQI) information to be transmitted from a physical layer to a media access control (MAC) layer by using the AGC index, when the CCA status is high, in order to embody effective piconets in a multi-band orthogonal frequency division multiplexing ultra-wide band system (MB-OFDM UWB system) including a receiver having a dynamic gain controller(DGC) and the AGC.
摘要:
A digital phase-locked loop apparatus using FSK includes a PFD detecting phase differences between a reference clock and a frequency-divided signal, and a first adder for generating first digital control codes by adding first digital codes, second digital codes, and channel frequency codes including channel information to each other, the first digital codes being converted from time differences between first and second pulses. The apparatus further includes a digital filter correcting errors of the first digital control codes to generate second digital control codes, a DCO for varying an oscillating frequency in accordance with a digital tuning word based on the second digital control codes, and a dual modulus division unit dividing the oscillating frequency into a frequency-divided signal.
摘要:
A transmitting apparatus groups a data bit sequence to groups each formed of a predetermined number of bits, modulates predetermined bits of one of groups through a frequency shift keying (FSK) modulation method, non-continuously aligns the FSK modulation signals, and transmits the non-continuous FSK modulation signals.
摘要:
A base station and a terminal for supporting a low power mode are provided. The base station transmits a first type of beacon signal for a terminal operating in a normal mode, a second type of beacon signal for a terminal operating in a low power mode, and a charging signal for a terminal in a low power mode. The terminal harvests energy from a charging signal and receives the second type of beacon signal using the harvested energy. The terminal confirms a communication request through the second type of beacon signal, enters into an active period, and communicates with the base station.
摘要:
In a local wireless communication system, a reception signal including an STF (short training field) in which a plurality of patterns are repeatedly transmitted is received, the STF including a first number of STF patterns and a second number of STF patterns, the second number of STF patterns having an opposite code to that of the first number of STF patterns. In a first frequency offset estimation and correction process and a second frequency offset estimation and correction process, frequency offset estimation is performed on a plurality of STF patterns to acquire a phase error of each sample constituting the STF patterns, and the frequency of the STF patterns is corrected based on the acquired phase error. Cross correlation is performed on a predetermined number of STF patterns, among a plurality of STF patterns output subsequent to the frequency offset estimation and correction, to detect frame timing.
摘要:
According to exemplary embodiments of the invention, a location-based keyword recommending system and method are provided. The location-based keyword recommending system may include a keyword collecting unit to store location information regarding a location where a keyword is input, a region setting unit to set a virtual region by performing clustering of the location information with reference to the keyword, a region combining unit to combine virtual regions overlapping each other into one virtual region, and a keyword recommending unit to provide a location-based keyword based on the keyword related to the location information of the virtual region.