I have recently bought a LimeSDR-USB which I would like to use for sending a defined length TX RF pulse at 3MHz. I am currently using pyLMS7002Soapy to communicate with the limeSDR and to adjust the NCO Frequency to mix down.
from pyLMS7002Soapy import *
from SoapySDR import * # SOAPY_SDR_ constants
import numpy as np
sdr.sdr.setSampleRate(SOAPY_SDR_TX, 0, 50e6)
sdr.txRfFreq = 120e6
sdr.txNCOFreq = 117e6
sdr.txGain = 60
TxTSP = sdr.LMS7002.TxTSP['A']
TxTSP.TSGMODE = "DC"
txTimeout = 100000
txFlags = SOAPY_SDR_HAS_TIME | SOAPY_SDR_END_BURST
txStream = sdr.sdr.setupStream(SOAPY_SDR_TX, SOAPY_SDR_CF32, )
numSamps = 1024
sdr.sdr.activateStream(txStream, SOAPY_SDR_END_BURST, numElems=numSamps)
x = np.linspace(-10, 10, numSamps)
txPulse = np.sinc(x) * 1/np.sinc(x).max()
txTime0 += long(0.1e6) #100ms timestamp to get the signal at specific time
sr = sdr.sdr.writeStream(txStream, [txPulse], txPulse.size, txFlags)
How can I define the pulse length of my Tx RF Pulse?
My application is NMR related, much similar to http://www.enc-conference.org/portals/0/Abstracts2018/ENC20187816.9238VER.3.pdf. Which software did the cMichal use to generate the RF pulse?
Thank you very much in advance, I have tried for around one week to get a similar output pulse on my LimeSDR-USB without success.
Please also answer - this is definitely not possible - or you could start here … ?!