Anti-interference signal detection and synchronization method for wireless broadband communication system

An anti-interference signal detection and synchronization method for a wireless broadband communication system, comprising:

• calculating a cross-correlation value of a received signal and a local sequence by using an equation (6), wherein the local sequence has a same structure as a training sequence structure, the training sequence structure comprises two repetitive short training sequences and two repetitive long training sequences, each of the short training sequence and the long training sequence is a pseudo-random sequence having autocorrelation which is expressed by an equation (5):
• R
• ⁡
• (
• m
• )
• =
• ∑
• n
• =
• 0
• M
• -
• 1
• ⁢
• x
• ⁡
• (
• n
• +
• m
• )
• ⁢
• x
• *
• ⁡
• (
• n
• )
• ⁢
• →
• m
• ≠
• 0
• ⁢
• 0
• (
• 5
• )
• wherein, m represents an offset of the sequence, M represents a length of the sequence, and (.)* represents a conjugate operation, the short training sequence has close cross-correlation with the long training sequence, the short training sequence is not correlated with the long training sequence,
• and wherein based on auto-correlation and cross-correlation of the long training sequence and the short training sequence, a cross-correlation function of the received signal and the local sequence is expressed by the equation (6):
• R(m)=Σn=0M-1yoffset(n+m)xLocal*(n) (6)
• wherein, M represents a length of the local sequence, m represents an offset of the local sequence, (.)* represents a conjugate operation, and xLocal*(n) represents a conjugate of the local sequence;
• determining two consecutive peak values separated from each other by a sequence length based on an absolute value of the cross-correlation function of the received signal and the local sequence, wherein the two consecutive peak values satisfy a relationship expressed by an equation (7):
• RΔ(M+m)=RΔ(m)ej2πM/N/N (7)
• wherein, RΔ(m) represents a peak value of a cross-correlation curve of the received signal and the local sequence, M represents the length of the sequence, ε represents a normalized frequency offset, and j=√{square root over (−1)};
• and
• obtaining an estimated value {circumflex over (ε)} of the normalized frequency offset ε based on the equation (7):
• ɛ
• ^
• =
• N
• M
• ⁢
• ⁢
• 2
• ⁢
• ⁢
• π
• ⁢
• ∡
• ⁡
• (
• R
• Δ
• ⁡
• (
• M
• +
• m
• )
• ⁢
• conj
• ⁡
• (
• R
• Δ
• ⁡
• (
• m
• )
• )
• )
• (
• 8
• )
• wherein, conj(.) represents a conjugate operation, and ∠ represents an operation for obtaining a phase between (0,2π], and
• wherein the calculating the cross-correlation value by using the equation (6) comprises calculating the cross-correlation value by using an equation (9):
• R(m)=Σn=0∞yoffset(n+m)xLocal*(n)=yoffset(n)⊗xLocal(−n) (9)
• wherein, xLocal*(n) represents the conjugate of the local sequence, yoffset(n) represents a time domain sample of the received signal, and ⊗ represents a convolution operation.