Plutonium94
Member
Hello. I'm doing research about P25 Common Air Interface and encryption protocols. I'm new to using OP25, so please be understandable if I'm wrong about something.
When I turn the logging up to -v 10, I can see the codewords and all the other info, but it's all messy. I think I'm missing something in that point.
Also, I'd like to know if there is any way to decode the voice code word (144 bit) to get the "clean" voice frame (88 bit). I do know that voice frames are encoded into a 144 bit voice code word using Golay and Hamming codes. The 48 most important bits (u_0 through u_3) are error protected with four (23,12,7) Golay code words. The next 33 most significant bits (u_4 through u_6) are error protected with three (15,11,3) Hamming code words. The last 7 least significant bits (u_7) are not error protected. So, in other words, I'd need to decode all error control codes (Hamming and Golay) to produce the voice data vectors (u_0 through u_7), if this is possible using OP25.
Thank you!
When I turn the logging up to -v 10, I can see the codewords and all the other info, but it's all messy. I think I'm missing something in that point.
Also, I'd like to know if there is any way to decode the voice code word (144 bit) to get the "clean" voice frame (88 bit). I do know that voice frames are encoded into a 144 bit voice code word using Golay and Hamming codes. The 48 most important bits (u_0 through u_3) are error protected with four (23,12,7) Golay code words. The next 33 most significant bits (u_4 through u_6) are error protected with three (15,11,3) Hamming code words. The last 7 least significant bits (u_7) are not error protected. So, in other words, I'd need to decode all error control codes (Hamming and Golay) to produce the voice data vectors (u_0 through u_7), if this is possible using OP25.
Thank you!