Dear Marcus There are one 5 Mhz modulated bandwidth centered and transmited on 1ghz . in the cable i add 1 Mhz modulated bandwidth centered in the same occupied bandwidth for example 1ghz or 1.001 ghz or .. i want do some thing like this in satellites link : http://www.newtec.eu/frontend/files/leaflet/bwc0900-bandwidth-canceller.pdf
Thank you . On Sun, Aug 20, 2017 at 8:41 PM, mohammad nejati <tufa...@gmail.com> wrote: > 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 , _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
