| 主权项 |
1. A channel and noise estimation method, applied to a channel and noise estimation apparatus of a wireless communication system, the channel and noise estimation method comprising:
performing channel estimation on a received signal to obtain a real channel estimation value; filtering the real channel estimation value to obtain a filtered channel estimation value; calculating a biased noise power value, a biased signal power value, a biased noise correlation and a biased signal correlation according to the filtered channel estimation value; and respectively calculating an unbiased noise power value, an unbiased signal power value, an unbiased noise correlation and an unbiased signal correlation according to the biased noise power value, the biased signal power value, the biased noise correlation and the biased signal correlation by using a first inverted matrix; wherein the step of performing the channel estimation on the received signal to obtain the real channel estimation value comprises:
performing the channel estimation on at least one signal received by a first reception antenna and a second reception antenna, respectively, to obtain corresponding real channel estimation values HLS1 and HLS2, where HLS1 represents the real channel estimation value corresponding to the first reception antenna, and HLS2 represents the real channel estimation value corresponding to the second reception antenna; wherein the step of filtering the real channel estimation value to obtain the filtered channel estimation value comprises:
filtering the real channel estimation values HLS1 and HLS2 by utilizing a first filter and a second filter, respectively, to obtain corresponding filtered channel estimation values Yw1(k), Yw2(k), Yu1(k) and Yu2(k), where Yw1(k) represents the filtered channel estimation value obtained from filtering HLS1 by the first filter, Yw2(k) represents the filtered channel estimation value obtained from filtering HLS2 by the first filter, Yu1(k) represents the filtered channel estimation value obtained from filtering HLS1 by the second filter, and Yu2(k) represents the filtered channel estimation value obtained from filtering HLS2 by the second filter; wherein values of HLS1 and HLS2 are:
HLS1=Hideal1+v1 (1)HLS2=Hideal2+v2 (2)where Hideal1 represents an ideal channel estimation value of the first reception antenna, v1 represents a noise value of the first reception antenna, Hideal2 represents an ideal channel estimation value of the second reception antenna, and v2 represents a noise value of the second reception antenna; andvalues of Yw1(k), Yw2(k), Yu1(k) and Yu2(k) are calculated through following equations:
Yw1(k)=wHLS1 (3)Yw2(k)=wHLS2 (4)Yu1(k)=uHLS1 (5)Yu2(k)=uHLS2 (6)where w represents a coefficient row vector of the first filter, k represents a kth subcarrier on a frequency domain, and u represents a coefficient row vector of the second filter; and wherein the step of calculating the biased noise power value, the biased signal power value, the biased noise correlation and the biased signal correlation according to the filtered channel estimation value comprises:
calculating biased noise power values Sw1 and Sw2, biased signal power values Su1 and Su2, a biased noise correlation Pw12 between Yw1(k) and Yw2(k), and a biased signal correlation Pu12 between Yu1(k) and Yu2(k) corresponding to the first reception antenna and the second reception antenna according to Yw1(k), Yw2(k), Yu1(k) and Yu1(k), respectively; andvalues of Sw1, Sw2, Su1, Su2, Pw12 and Pu12 are calculated through following equations:
Sw1=Ek(Yw1(k)·Yw1(k)*) (7)Sw2=Ek(Yw2(k)·Yw2(k)*) (8)Su1=Ek(Yu1(k)·Yu1(k)*) (9)Su2=Ek(Yu2(k)·Yu2(k)*) (10)Pw12=Ek(Yw1(k)·Yw2(k)*) (11)Pu12=Ek(Yu1(k)·Yu2(k)*) (12)where Sw1 represents the biased noise power value corresponding to the first reception antenna, Sw2 represents the biased noise power value corresponding to the second reception antenna, Su1 represents the biased signal power value corresponding to the first reception antenna, Su2 represents the biased signal power value corresponding to the second reception antenna, Pw12 represents the biased noise correlation between Yw1(k) and Yw2(k), Pu12 represents the biased signal correlation between Yu1(k) and Yu2(k), Ek(●) represents a frequency-domain average, and (●)* represents a conjugation; and wherein after the step of calculating the unbiased noise power value, the unbiased signal power value, the unbiased noise correlation and the unbiased signal correlation according to the biased noise power value, the biased signal power value, the biased noise correlation and the biased signal correlation, the method further comprising:
frequency-domain smoothing the unbiased noise power value, the unbiased signal power value, the unbiased noise correlation and the unbiased signal correlation;time-domain filtering the frequency-domain smoothed unbiased noise power value, unbiased signal power value, unbiased noise correlation and unbiased signal correlation; anddemodulating the filtered unbiased noise power value, unbiased signal power value, unbiased noise correlation and unbiased signal correlation to restore an original transmission signal. |
