Patent ID: 8837614

Claim:
A pilot-based timing offset estimation apparatus, comprising: a pilot bit channel estimation module, configured to acquire pilot bit frequency-domain channel estimation values of target users through calculation on respective sub-carriers of the target users according to received frequency-domain demodulation reference symbols and local frequency-domain demodulation reference symbols; and a timing offset estimation module, configured to respectively perform timing offset estimation for each target user by using phase differences among the pilot bit frequency-domain channel estimation values on the respective sub-carriers; wherein the timing offset estimation module calculates timing offset estimation values at respective pilot positions on respective receiving antennae by using the phase differences among the acquired pilot bit frequency-domain channel estimation values; wherein the timing offset estimation module averages a plurality of the timing offset estimation values at the pilot positions on the receiving antennae acquired through calculation; wherein the timing offset estimation module calculates the timing offset estimation value t 0,slot — i,ka,(m) of a time slot slot_i of a k th sub-carrier of an m th user of a ka th antenna according to the formula as follows: t 0 , slot ⁢ ⁢ _ ⁢ ⁢ i , ka , ( m ) = N 2 ⁢ π * 1 M - S * 1 S * ( ∑ k = 1 M - S ⁢ angle ⁡ ( H k , slot ⁢ ⁢ _ ⁢ ⁢ i , ka ⁡ ( m ) * conj ⁡ ( H k + S , slot ⁢ ⁢ _ ⁢ ⁢ i , ka , ( m ) ) ) ) where M is a length of a frequency-domain channel estimation value; N is the number of points of a Fast Fourier Transform (FFT); S is a carrier spacing factor which is an integer less than M-S, and when a cell configuration is a normal cyclic prefix, S is selected to be a first value by default, and when a cell configuration is an extended cyclic prefix, S is selected to be a second value by default; “angle ( )” is an angle function; “conj( )” is a conjugate function; H k,slot — i,ka,(m) is a frequency-domain channel estimation value of the time slot slot_i of the k th sub-carrier of the m th user of the ka th antenna; and H k+S,slot — i,ka,(m) is a frequency-domain channel estimation value of the time slot slot_i of the k+s th sub-carrier of the m th user of the ka th antenna.