US 12,259,478 B2
Injecting an arbitrary IQ stream into a test environment
Felix Michael Krefft, Paignton (GB); Stephen Nigel Beales, Paignton (GB); and Mark Geoffrey Holbrow, Paignton (GB)
Assigned to Spirent Communications, PLC, Crawley (GB)
Filed by Spirent Communications, PLC, Crawley (GB)
Filed on Apr. 29, 2022, as Appl. No. 17/733,770.
Prior Publication US 2023/0350072 A1, Nov. 2, 2023
Int. Cl. G01S 19/01 (2010.01); G01S 19/02 (2010.01); G01S 19/23 (2010.01); G01S 19/25 (2010.01); G01S 19/51 (2010.01)
CPC G01S 19/015 (2013.01) [G01S 19/02 (2013.01); G01S 19/23 (2013.01); G01S 19/254 (2013.01); G01S 19/51 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A method of incorporating an IQ stream into a test signal used to test a receiver in motion, wherein the IQ stream represents an interference transmitter without representing the motion of the receiver in motion, the method including:
configuring the test, including:
configuring a path for the motion of the receiver during simulation;
configuring a period of the simulation that includes time corresponding to start time;
configuring at least one transmitter constellation to emulate during the simulation; and
configuring a location of or path for motion of at least one IQ stream transmitter of the IQ stream during the simulation;
generating signals emulating the transmitter constellation;
conditioning the IQ stream to be merged with the signals emulating the transmitter constellation, including:
using distance and relative motion between the receiver and the IQ stream transmitter to determine delay and Doppler frequency shift between the IQ stream transmitter and the receiver in motion;
scheduling sampling of the IQ stream, including interpolation among samples of the IQ stream, taking into account the delay and the Doppler frequency shift; and
synthesizing a conditioned IQ stream from the interpolation among the samples, further taking into account signal level of the conditioned IQ stream, in addition to the delay and the Doppler frequency shift;
merging the conditioned IQ stream with the signals emulating the transmitter constellation; and
supplying the merged signals to the receiver during the test.