本人在扩频载波同步中(已经伪码同步),利用锁相环进行载波相位的跟踪,思路是是用利用I路、Q路相关累加后,用coridc进行了atan得出相位差。现在问题是怎么我看到有人是在atan之前先对I路、Q路相关累值进行了变换处理。如下:
process(clk)
begin
if (clk'event and clk='1') then
if (correlation_I(20) = '1') then --correlation_I(20)是符号位
correlation_I_cordic <= (not correlation_I)+'1';
correlation_Q_cordic <= correlation_Q;
else
correlation_I_cordic <= correlation_I;
correlation_Q_cordic <= (not correlation_Q)+'1';
end if;
end if;
end process;