Re: Round trip time calculation - simulation
Hi Jiya, some inline comments. On 31.08.23 12:35, Jiya Johnson wrote: Hi Johannes, Thanks in advance for your valuable inputs! I appreciate your help so much. 1.I want to measure the time taken by 1 sample from the random source to the decoder unit-endpoint. My previous comment was targeted at the fact that FEC encoders and decoders work on blocks or frames. The concept of single samples or bits and how long they take to propagate through a flowgraph is probably not a good measure. It would probably make more sense to look at FEC frames and how long they take to propagate through a flowgraph. Depending on the exact position in your flowgraph, an FEC frame might imply that these are the info bits or a codeword. 2.Need more clarifications in throttle usage in terms of latency. The throttle block measures how many samples it passed to the output during a time period and will just stall if more samples could pass through. The GR buffer architecture tries to fill buffers. If you stall in any part of the flowgraph, it might take longer until your blocks where you want to measure latency are called by the scheduler. 3.Time stamp i have used is with two stamping before encoding and after decoding whether it will make sense ,what i understood is time delta if i am using it will be taking only the latest time key added. The "Add System Time" block is intended to be used together with https://github.com/gnuradio/gnuradio/blob/main/gr-pdu/include/gnuradio/pdu/time_delta.h There's a nice explanation in the wiki: https://wiki.gnuradio.org/index.php/Time_Delta 4.How can i use the control performance monitor for this FG. GNU Radio Companion 3.10.7.0 performance monitor is intended for things like load and buffer state. Latency needs extra info (the discussed timestamps). Thus, performance monitor won't report latency. I will upload a PDF of the flowgraph. smime.p7s Description: S/MIME Cryptographic Signature
i have question about uhd:usrp sink block 's bandwidth
hello i have a question about relation between sample rate of UHD USRP SINK block and CPU i am currently implement MIMO OFDM Radar system at gnuradio(ubuntu) and USRP X310 and UBX160 daughter board with 10gbit ethernet with connected by sfp cable as i read at ettus official manual it can handle 160Mhz Bandwith and usrp's bw is related with sample rate as this equation bw=0.8 x (samplerate) when i using 100Mhz sample rate for single input single output radar system it works well but when i using same sample rate at MIMO version of same radar then Gnuradio stops with error code as i under stand this error code means L: Tx: "Late data (arrived after indicated time)". Rx (RFNoC only?): "Late command (stream command arrived after indicated time) then i changed sample rate by 50Mhz then MIMO system works well so i asked about this to NI(ettus) as i know my USRP x310 and ubx160 daughter board can handle 160Mhz but why it stops? they answered that i could be your desktops performance can't handle that sample rate then i checked my computer's cpu usage when using 100Mhz it really using every resource of my cpu so i can figure it out that for more sample rate high spec CPU is needed but i can't find which spec(clock rate, number of core, threads) is important for more 100Mhz sample rate and what's the minimum CPU spec for running my system using 100Mhz samplerate soif anyone knows about this... I understand everyone must be busy, but I would greatly appreciate it if you could spare a little time to help. and Thanks for read this long text...
Round trip time calculation - simulation
Hi Johannes, Thanks in advance for your valuable inputs! I appreciate your help so much. 1.I want to measure the time taken by 1 sample from the random source to the decoder unit-endpoint. 2.Need more clarifications in throttle usage in terms of latency. 3.Time stamp i have used is with two stamping before encoding and after decoding whether it will make sense ,what i understood is time delta if i am using it will be taking only the latest time key added. 4.How can i use the control performance monitor for this FG. GNU Radio Companion 3.10.7.0 I will upload a PDF of the flowgraph. Latency_CCSDS.pdf Description: Adobe PDF document
