FSK DECODING USING ENVELOP COMPARISON IN THE DIGITAL DOMAIN

A method of FSK decoding includes generating a pulse waveform (R'Edge) from a received FSK encoded signal (FSK signal) (101) and a system clock (Sys_clk). From R'Edge and Sys_clk clocks are generatedby clock generator (115) including a first clock and second clock framing a logic '0' level of the FSK signal, and a third clock and fourth clock framing a logic '1' level of the FSK signal. At leastfour frequency envelops are generated from the clocks by envelop generator (120) including a logic '0' envelop, a logic '1' envelop, a lower frequency envelop below the logic '0' envelop, and an upperfrequency envelop above the logic '1' envelop. R'Edge is compared to the four envelops by comparator (125), and a decoded output (130) is produced, logic '0' if the R'Edge overlaps the logic '0' envelop, logic '1' if R'Edge overlaps the logic '1' envelop, and a previous output state if R'Edge does not overlap the logic '0' or logic '1' envelop. 种FSK解码的方法包括从接收到的经FSK编码的信号（FSK信号）（101）和系统时钟（Sys_clk）生成脉冲波形（R'边沿）。从R'边沿和Sys_clk由时