1. What are the contributions in "Blind maximum-likelihood carrier-frequency-offset estimation for interleaved ofdma uplink systems" ?
In this paper, the authors propose a new method to solve the problem.
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2. What future works have the authors mentioned in the paper "Blind maximum-likelihood carrier-frequency-offset estimation for interleaved ofdma uplink systems" ?
It is interesting to incorporate the SAGE algorithm into the proposed method, which may serve as a topic for further research.. Then, the first term in the right-hand side of ( 9 ) can be derived as ( R−1y ∂ ∂εe, i Ry ) p, q = Q∑ k=1 ( R−1y ) p, k j2πNσ2x Ns ( k − q ) w ( εe, i ) N ( k−q ) = j2πNσ2x. Ns { σ−2η w ( εe, i ) N ( p−q ) − C0 Q∑ k=1 ( k − q ) xk−qΓ ( p, k ) − C1 Q∑ k=1 Q∑ b=1 ( k − q ) xk−qΓ ( p, b ) Γ ( b, k ) − C2 Q∑ k=1 ( k − q ) xk−q · Q∑ a=1 Q∑ b=1 Γ ( p, a ) Γ ( a, b ) Γ ( b, k ) } ( 50 ) where x = exp ( j2π Nεe, i Ns ). ( 51 ) To obtain the second term in ( 9 ), the derivative of the third and fourth terms in the right-hand side of ( 17 ) can first be found as ∂ ∂εe, i { Q∑ n=1 Γ ( n, q ) Γ ( p, n ) } = j2πN Ns [ Q∑ n=1 ( n − q ) Γ ( p, n ) w ( εe, i ) N ( n−q ) + ( p − n ) Γ ( n, q ) w ( εe, i ) N ( p−n ) ] ( 52 ) ∂ ∂εe, i { Q∑ m=1 Q∑ n=1 Γ ( m, n ) Γ ( n, q ) Γ ( p, m ) } = j2πN Ns [ Q∑ m=1 Γ ( p, m ) Q∑ n=1 Γ ( n, q ) · ( m − n ) w ( εe, i ) N ( m−n ) + ( n − q ) Γ ( p, m ) Γ ( m, n ) w ( εe, i ) N ( n−q ) + ( p − m ) Γ ( m, n ) Γ ( n, q ) w ( εe, i ) N ( p−m ) ]. ( 53 ) Thus, the authors can have the second term in ( 9 ) as ( 54 ), shown at the bottom of the page.. Substituting ( 3 ), ( 5 ), ( 50 ), and ( 54 ) into ( 9 ), the authors can rewrite the log-likelihood function as ( 55 ), shown at the bottom of the page.
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