Hi , It is difficult to explain what i need but i want to try it . I have a single modulated carrier with 5 Mhz bandwidth i send it throw cable and receive delayed version of that with a good SNR like 45dB .
I store i/q sample in last stage of transmitter , In cable i add one 1 Mhz carrier with lower power into exactly 5 mhz equipped bandwidth of carrier (1Mhz carrier is hidden in 5 Mhz carrier due to lower signal power) . what i want to do is in receiver subtract transited signal from received signal in a proper delay and phase and recover 1 Mhz carrier . I use LMS algorithm for adaption and subtraction and that work only when received i/q sample have exactly same center frequency with stored transmitted i/q sample which in reality with SDR board and zero if architecture it is almost impossible . i don't want find center frequency of received carrier with method like costas loop , because modulated signal may have difference modulation like 64 QAM , 16 QAM , 32APSK , BPSK ... i want find and lock received center frequency and phase with help of that i stored a correct version of that before transmit . i attached an image of subtracted signal and recovered smaller carrier (which is in an ideal condition without frequency drift). Thank you ,
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