For Multi-Carrier-Code Division Multiple Access （MC-CDMA） systems, it is usually assumed that the fading of the subcarriers is frequency non-selective and independent of each other. This paper shows that the two ass...For Multi-Carrier-Code Division Multiple Access （MC-CDMA） systems, it is usually assumed that the fading of the subcarriers is frequency non-selective and independent of each other. This paper shows that the two assumptions are incompatible. In fact, the MC-CDMA signals at each subcarrier undergo fading that are highly correlated. Based on this observation, this paper develops a simulation algorithm for Rayleigh fading channels via frequency-domain correlation functionl which incorporates the Doppler effect simultaneously. Numerical examples are presented to demonstrate the effectiveness of the new algorithm, with the conclusion that the independence assumption of subcarrier fading overrates the system performance.展开更多
The changes of the positive rate in cases with frequency domain-correlative cardiogramIFCG) grade 7 were evaluated with electrocardiographic autopower spectrum function before and afterQigong exercise. Seventeen sub...The changes of the positive rate in cases with frequency domain-correlative cardiogramIFCG) grade 7 were evaluated with electrocardiographic autopower spectrum function before and afterQigong exercise. Seventeen subjects, aged from 54 to 72 ( mean 66) , 5 males and 12 temales, underwentQigong exercises for 65 to 103 days, and were tested by FCG to compare with pre Qigong exercise status.The results show the positive rate of abnormal elecctrocardiographic autopower spectrum function of lead V5(Gxx 1/2) decreased from 59% (10/17) to 0% (0/17) and lead (GYY 1/2) decreased from 82% (14/17) to 41% (7/17) , P<0. 01 and 0. 05. This study suggests Qigong exercises could significantly decreasethe positive rate of abnormal electrocardiographic autopower spectrurn function and improve coronary perfu-sion or left ventricular dystunction produced by myocardial ischemia.展开更多
基金Supported by the Major Program of the National Natural Science Foundation of China (No.60496311).
文摘For Multi-Carrier-Code Division Multiple Access （MC-CDMA） systems, it is usually assumed that the fading of the subcarriers is frequency non-selective and independent of each other. This paper shows that the two assumptions are incompatible. In fact, the MC-CDMA signals at each subcarrier undergo fading that are highly correlated. Based on this observation, this paper develops a simulation algorithm for Rayleigh fading channels via frequency-domain correlation functionl which incorporates the Doppler effect simultaneously. Numerical examples are presented to demonstrate the effectiveness of the new algorithm, with the conclusion that the independence assumption of subcarrier fading overrates the system performance.
文摘The changes of the positive rate in cases with frequency domain-correlative cardiogramIFCG) grade 7 were evaluated with electrocardiographic autopower spectrum function before and afterQigong exercise. Seventeen subjects, aged from 54 to 72 ( mean 66) , 5 males and 12 temales, underwentQigong exercises for 65 to 103 days, and were tested by FCG to compare with pre Qigong exercise status.The results show the positive rate of abnormal elecctrocardiographic autopower spectrum function of lead V5(Gxx 1/2) decreased from 59% (10/17) to 0% (0/17) and lead (GYY 1/2) decreased from 82% (14/17) to 41% (7/17) , P<0. 01 and 0. 05. This study suggests Qigong exercises could significantly decreasethe positive rate of abnormal electrocardiographic autopower spectrurn function and improve coronary perfu-sion or left ventricular dystunction produced by myocardial ischemia.
