Abstract: A cathode active material for a lithium secondary battery according to an embodiment of the present disclosure includes first lithium metal phosphate particles, each first lithium metal phosphate particle having a secondary particle shape formed by aggregation of primary particles and having an average particle diameter (D50) in a range from 5 ?m to 10 ?m, second lithium metal phosphate particles, each having a single particle and having an average particle diameter in a range from 1 ?m to 3 ?m, and third lithium metal phosphate particles, each having a single particle shape and having an average particle diameter less than 1 ?m.

Abstract: An apparatus for detecting a guard interval length (type) of a transmission symbol among the structure of an orthogonal frequency division multiplexing (OFDM) system receiver, to ensure proper operation of a symbol start detector and a fast Fourier transform (FFT) window position controller, is provided.

Abstract: An apparatus for detecting a guard interval length (type) of a transmission symbol among the structure of an orthogonal frequency division multiplexing (OFDM) system receiver, to ensure proper operation of a symbol start detector and a fast Fourier transform (FFT) window position controller, is provided.

Abstract: An apparatus for detecting a guard interval length (type) of a transmission symbol among the structure of an orthogonal frequency division multiplexing (OFDM) system receiver, to ensure proper operation of a symbol start detector and a fast Fourier transform (FFT) window position controller, is provided.

Abstract: An OFDM receiver for interlocking FFT window position recovery with sampling clock control, and a method thereof are provided. This method includes the steps of: extracting a pilot signal from fast-Fourier-transformed OFDM received signals, and detecting inter-pilot phase differences; averaging the detected phase differences for a symbol and normalizing the mean phase difference by dividing it into reference values corresponding to phase differences generated when FFT window errors of at least one sample exist; and simultaneously controlling the FFT window position offset using a value obtained by rounding off the normalized value, and the sampling clock offset using the difference between the round-off value and the normalized value.

Abstract: A fast Fourier transform (FFT) window position recovery apparatus in an orthogonal frequency division multiplexing (OFDM) receiver is provided. This apparatus, in an OFDM system receiver which receives an OFDM symbol comprised of a useful data interval and a guard interval and recovers a FFT window position, includes: an analog-to-digital converter (ADC) for converting a received OFDM signal into a digital complex sample; a symbol start detector for detecting a power difference between the digital complex samples output by the ADC and detecting a position having a minimum absolute value of the power difference between the samples, as a symbol starting position; and a FFT window controller for activating FFT by moving the FFT window position using symbol start information detected by the symbol start detector. The influence of frequency and phase offsets is reduced by using the power difference between adjacent samples delayed by the useful data interval, thus improving the reliability of a system.

Abstract: A fine fast Fourier transform window position recovering apparatus of an OFDM system receiver for recovering the phase error of an FFT window by using the number of zero-crossings of the phase variation value calculated between transmitted and received complex values is provided. The fine FFT window position recovering apparatus includes: an analog to digital converter, a symbol start detector, an FFT means, a phase calculator, a zero-crossing counter and an FFT window controller. The apparatus makes it possible to guarantee the reliability of a system by adjusting the phase error of the FFT window by using the number of zero-crossings of the phase variation calculated between the transmitted and received complex values and the number of the zero-crossings of the amplitude of the real part or the imaginary part of the received complex value.