Patent ID: 8548101

Claim:
A demodulation method for an Orthogonal Frequency Division Multiplexing (OFDM)-Multiple Input Multiple Output (MIMO) system, comprising: a) by using a received reference signal, carrying out estimation to obtain a channel estimation value at a reference signal sub-carrier in each channel; b) by using the channel estimation value at the reference signal sub-carrier in each channel, carrying out calculation to obtain an equalization matrix at the reference signal sub-carrier; c) by using the equalization matrix obtained by calculation to carry out an interpolation calculation, obtaining the equalization matrixes at all of data sub-carriers; d) by using data signals in various paths received from all of the data sub-carriers and corresponding equalization matrixes, carrying out calculation to obtain an intermediate estimation value of transmitted data; and e) by using a precoding matrix to carry out de-precoding on the intermediate estimation value of the transmitted data, obtaining a final estimation value of the transmitted data; wherein, in the step d), carry out calculation to obtain the intermediate estimation value of the transmitted data by employing a following formula: ( V ~ 0 ⁡ [ i , k ] V ~ 1 ⁡ [ i , k ] ) = G ⁡ ( i , k ) ⁢ ( Y 0 ⁡ [ i , k ] Y 1 ⁡ [ i , k ] ) wherein, {tilde over (V)} 0 [i,k] and {tilde over (V)} 1 [i,k] are respectively intermediate estimation values of transmitted signals in 0 th path and 1 st path at a k th data sub-carrier within an i th OFDM symbol, G(i,k) is an equalization matrix at the k th data sub-carrier within the i th OFDM symbol obtained in the step c), Y 0 [i,k] and Y 1 [i,k] are data signals in the 0 th path and 1 st path received at the k th data sub-carrier within the i th OFDM symbol respectively, k is a sequence number of sub-carrier, i is a sequence number of the OFDM symbol and k,i are both integers; in the step e), carry out calculation to obtain the final estimation value of the transmitted data by employing a following formula: ( X ~ 0 ⁡ [ i , k ] X ~ 1 ⁡ [ i , k ] ) = W H ⁡ ( i , k ) ⁢ ( V ~ 0 ⁡ [ i , k ] V ~ 1 ⁡ [ i , k ] ) wherein, {tilde over (X)} 0 [i,k] and {tilde over (X)} 1 [i,k] are estimation values of transmitted data in the 0 th path and 1 st path at the k th data sub-carrier within the i th OFDM symbol respectively, W(i,k) is a precoding matrix at the k th data sub-carrier within the i th OFDM symbol and W H (i,k) is a conjugate transposed matrix of W(i,k).