Patent ID: 7039132

Claim:
A baseband circuit for estimating a binary sequence b(k)={{circumflex over (b)} 0 , {circumflex over (b)} 1 , {circumflex over (b)} 2 , . . . , {circumflex over (b)} k−2 , {circumflex over (b)} k−1 , {circumflex over (b)} k , {circumflex over (b)} k+1 , . . . } in a GFSK (Gaussian Frequency Shift Keying) communication system, comprising: a carrier synchronization circuit, responsive to a complex baseband signal z k,j and a preamble data t(k), for generating a frequency offset estimation {circumflex over (Ω)} Δ , wherein z k,j representing a j-th sample of a k-th symbol of a received data, 0≦j≦N−1, N representing samples per symbol; a clock synchronization circuit, responsive to the complex baseband signal z k,j and the frequency offset estimation {circumflex over (Ω)} 66 , for generating a complex digital decimated signal z k,ĵ by estimating a sampling point ĵ; a demodulation circuit with decision feedback, responsive to the complex digital decimated signal z k,ĵ , the frequency offset estimation {circumflex over (Ω)} Δ , a first bit {circumflex over (b)} k−1 and a second bit {circumflex over (b)} k−2 , for demodulating the complex digital decimated signal z k,ĵ to generate the binary sequence b(k)={{circumflex over (b)} 0 , {circumflex over (b)} 1 , {circumflex over (b)} 2 , . . . , {circumflex over (b)} k−2 , {circumflex over (b)} k−1 , {circumflex over (b)} k , {circumflex over (b)} k+1 , . . . }; and a frame synchronization circuit, responsive to the binary sequence b(k)={{circumflex over (b)} 0 , {circumflex over (b)} 1 , {circumflex over (b)} 2 , . . . , {circumflex over (b)} k−2 , {circumflex over (b)} k−1 , {circumflex over (b)} k , {circumflex over (b)} k+1 , . . . } and the preamble data t(k), for obtaining a starting bit {circumflex over (b)} {circumflex over (k)} of the binary sequence b(k)={{circumflex over (b)} 0 , {circumflex over (b)} 1 , {circumflex over (b)} 2 , . . . , {circumflex over (b)} k−2 , {circumflex over (b)} k−1 , {circumflex over (b)} k , {circumflex over (b)} k+1 , . . . }.