Patent ID: 7492750

Claim:
A method for estimating noise variance, the method comprising: performing channel estimation on a midamble portion of a received burst to obtain a plurality of channel coefficients where active midambles are not known; and estimating noise variance based on equation σ ^ n 2 = T · ∑ i = l N sample ⁢  h n ⁡ ( i )  2 , where T = G · γ ⁡ ( r ) N sample , r = N sample L chest , N sample =L chest −N pl ·K max , h n(i) , (i=1,2,. . .,L chest ), represents channel coefficients, L chest is an output length of the channel estimation, N pl is a maximum number of paths per channel, K max is a maximum number of midamble shifts, n(i) is an index of i-th smallest estimated channel coefficient, G is a burst-dependent constant, γ ⁡ ( r ) = ⌊ 1 + ( 1 r - 1 ) · ln ⁡ ( 1 - r ) ⌋ - 1 , and i is an index.