mhostetter
commented
7 months ago You need to lower the sample rate to reduce the overflows. The overflows will drop samples, which can corrupt packets and lead to CRC failures.
Open hee910224 opened 7 months ago
mhostetter
commented
7 months ago You need to lower the sample rate to reduce the overflows. The overflows will drop samples, which can corrupt packets and lead to CRC failures.
Hello, I'm asking because I haven't solved the problem in a few days. I used a translator because I was not good at English.
I'm trying to do "ni USRP 2900" ads-b communication in window 10.
I installed gnuradio directly from Windows 10 and USRP from ni, so I use it without Cmake or any other build work you uploaded.
When I used the code you posted on the git, the message below appeared and overflow continued. "Ousrp_source :error: In the last 758 ms, 3 overflows occurred." Then, I changed the sample rate and several values, and when I first run the program, I get the data as shown below.
[INFO] [UHD] Win32; Microsoft Visual C++ version 14.2; Boost_107800; UHD_4.4.0.0-release [INFO] [B200] Detected Device: B200 [INFO] [B200] Operating over USB 3. [INFO] [B200] Initialize CODEC control... [INFO] [B200] Initialize Radio control... [INFO] [B200] Performing register loopback test... [INFO] [B200] Register loopback test passed [INFO] [B200] Setting master clock rate selection to 'automatic'. [INFO] [B200] Asking for clock rate 16.000000 MHz... [INFO] [B200] Actually got clock rate 16.000000 MHz. [INFO] [B200] Asking for clock rate 40.000000 MHz... [INFO] [B200] Actually got clock rate 40.000000 MHz. [INFO] ---------------------------------------------------------------------- [INFO] [1m[35mDatetime[0m: [22m2023-11-10 02:17:34.567997 UTC[0m[0m [INFO] [1m[35mSNR[0m: [22m15.80 dB[0m[0m [INFO] [1m[35mDownlink Format (DF)[0m: [22m26[0m [2mReserved[0m[0m [DEBUG] [1m[32mDF[0m: [22m26[0m [2mUnknown DF[0m[0m [INFO] ---------------------------------------------------------------------- [INFO] [1m[35mDatetime[0m: [22m2023-11-10 02:17:34.568097 UTC[0m[0m [INFO] [1m[35mSNR[0m: [22m11.22 dB[0m[0m [INFO] [1m[35mDownlink Format (DF)[0m: [22m25[0m [2mReserved[0m[0m [DEBUG] [1m[32mDF[0m: [22m25[0m [2mUnknown DF[0m[0m [INFO] ---------------------------------------------------------------------- [INFO] [1m[35mDatetime[0m: [22m2023-11-10 02:17:34.571209 UTC[0m[0m [INFO] [1m[35mSNR[0m: [22m13.69 dB[0m[0m [INFO] [1m[35mDownlink Format (DF)[0m: [22m16[0m [2mLong Air-Air Surveillance (ACAS)[0m[0m [INFO] [1m[35mCRC[0m: [22m[31mFailed[0m [2mUnrecognized AA from AP[0m[0m [INFO] [1m[35mAddress Announced (AA)[0m: [22m40ced8[0m[0m [DEBUG] [1m[32mFEC[0m: [22mConservative error correction lookup failed to get syndrome[0m[0m Ousrp_source :error: In the last 1129 ms, 1 overflows occurred. [INFO] ---------------------------------------------------------------------- [INFO] [1m[35mDatetime[0m: [22m2023-11-10 02:17:34.575103 UTC[0m[0m [INFO] [1m[35mSNR[0m: [22m16.10 dB[0m[0m [INFO] [1m[35mDownlink Format (DF)[0m: [22m6[0m [2mReserved[0m[0m [DEBUG] [1m[32mDF[0m: [22m6[0m [2mUnknown DF[0m[0mAs this data appears, the message CRC Failed continues to appear.
If you change the parameter value, the message below appears.
" [DEBUG] DF: 8 Unknown DF [DEBUG] DF: 3 Unknown DF [DEBUG] DF: 0 Unknown DF Ousrp_source :error: In the last 758 ms, 3 overflows occurred. [DEBUG] DF: 11 Unknown DF O[INFO] ---------------------------------------------------------------------- [INFO] Datetime: 2023-11-08 08:06:59.909242 UTC [INFO] SNR: 11.04 dB [INFO] Downlink Format (DF): 18 Extended Squitter/Non-Transponder [INFO] CRC: Failed PI^CRC = 16553477 [DEBUG] DF: 25 Unknown DF [DEBUG] DF: 3 Unknown DF O[INFO] ---------------------------------------------------------------------- [INFO] Datetime: 2023-11-08 08:07:00.077605 UTC [INFO] SNR: 8.57 dB [INFO] Downlink Format (DF): 19 Military Extended Squitter [INFO] CRC: Failed PI^CRC = 14293493 [DEBUG] DF: 28 Unknown DF [DEBUG] DF: 27 Unknown DF [INFO] ---------------------------------------------------------------------- [INFO] Datetime: 2023-11-08 08:07:00.147801 UTC [INFO] SNR: 5.91 dB [INFO] Downlink Format (DF): 17 Extended Squitter [INFO] CRC: Failed PI^CRC = 13570376 [DEBUG] DF: 0 Unknown DF [DEBUG] DF: 31 Unknown DF [INFO] ---------------------------------------------------------------------- [INFO] Datetime: 2023-11-08 08:07:00.222440 UTC [INFO] SNR: 10.50 dB [INFO] Downlink Format (DF): 18 Extended Squitter/Non-Transponder [INFO] CRC: Failed PI^CRC = 178647 OOusrp_source :error: In the last 841 ms, 4 overflows occurred. [DEBUG] DF: 8 Unknown DF OOO[DEBUG] DF: 23 Unknown DF [DEBUG] DF: 27 Unknown DF O[DEBUG] DF: 27 Unknown DF [DEBUG] DF: 11 Unknown DF Ousrp_source :error: In the last 832 ms, 5 overflows occurred. O[DEBUG] DF: 22 Unknown DF OO[DEBUG] DF: 14 Unknown DF [DEBUG] DF: 10 Unknown DF [DEBUG] DF: 16 Unknown DF O[DEBUG] DF: 11 Unknown DF " gnu adsb.zip
I don't know if this is a problem because the plane doesn't pass in my area or if it's an error in the code.
I can't find an answer when I Google "CRC error" from gnuradio.
Have you experienced any of the same problems with implementing ads-b?
I really want to solve it. Please help me!