Methods, systems and computer readable media for simulating per user equipment (UE) doppler shifts for testing air interface devices
View Patent ↗The subject matter described herein includes methods, systems, and computer readable media for simulating per-UE Doppler shifts. One exemplary method includes generating uplink signals to be transmitted from a plurality of different simulated UEs to an air interface device under test. The method further includes applying per-UE Doppler shifts to the signals, wherein applying per-UE Doppler shifts includes applying different Doppler shifts to at least some of the signals. The method further includes transmitting the signals to the air interface device under test.
1. A method for testing an air interface device using per user equipment (UE) Doppler shifted signals, the method comprising:
at a network equipment test device:
generating uplink signals including per-UE time domain uplink signals to be transmitted from plural simulated UEs to an air interface device under test;
applying per-UE Doppler shifts to the per-UE time domain uplink signals, wherein applying per-UE Doppler shifts to the per-UE time domain uplink signals includes applying different Doppler shifts to at least some of the per-UE time domain uplink signals, wherein applying per-UE Doppler shifts includes utilizing a plurality of per UE Doppler in the network equipment test device that apply Doppler shifts to the per-UE time domain uplink signals
performing discrete Fourier transformation and subcarrier mapping of the per-UE time domain, Doppler shifted uplink signals to produce a frequency domain entire bandwidth uplink signal;
performing inverse fast Fourier transformation of the frequency domain entire bandwidth uplink signal to produce a time domain entire bandwidth uplink signal; and
transmitting the time domain entire bandwidth uplink signal to the air interface device under test.
2. The method of claim 1 wherein generating uplink signals includes generating long term evolution (LTE) or LTE advanced uplink signals.
3. The method of claim 1 wherein generating uplink signals includes generating uplink reference signals, control channel signals, and data channel signals.
4. The method of claim 3 comprising applying Doppler shifts to the reference signals on a per-UE basis.
5. The method of claim 1 wherein applying the per-UE Doppler shifts to the per-UE time domain uplink signals includes simulating a Doppler shift for a UE moving towards a stationary device under test.
6. The method of claim 1 wherein applying the per-UE Doppler shifts to the per-UE time domain uplink signals in the time domain includes simulating a Doppler shift for a UE moving away from a stationary device under test.
7. The method of claim 1 wherein applying different Doppler shifts to at least some of the per-UE time domain uplink signals includes applying Doppler shifts that simulate UEs traveling at different velocities with respect to the air interface device under test.
8. The method of claim 1 wherein applying different Doppler shifts to at least some of the per-UE time domain uplink signals includes applying Doppler shifts that simulate UEs traveling in different directions with respect to the air interface device under test.
9. The method of claim 1 wherein the air interface device under test comprises an evolved Node B (e-Node B).
10. A system for testing an air interface device using per user equipment (UE) Doppler shifted signals, the system comprising:
a network equipment test device:
an uplink signal generator for generating uplink signals including per-UE time domain uplink signals to be transmitted from plural simulated UEs to an air interface device under test;
a plurality of per-UE Doppler shifters for applying per-UE Doppler shifts to the per-UE time domain uplink signals, wherein applying per-UE Doppler shifts includes applying different Doppler shifts to at least some of the per-UE time domain uplink signals, wherein applying per-UE Doppler shifts includes utilizing a plurality of per UE Doppler in the network equipment test device that apply Doppler shifts to the per-UE time domain uplink signals;
a plurality of discrete Fourier transformation units and a subcarrier mapping unit for respectively performing discrete Fourier transformation and subcarrier mapping of the per-UE time domain, Doppler shifted uplink signals to produce a frequency domain entire bandwidth uplink signal;
an inverse fast Fourier transformation (IFFT) unit for performing inverse fast Fourier transformation of the frequency domain entire bandwidth uplink signal to produce a time domain entire bandwidth uplink signal; and
a network interface for transmitting the time domain entire bandwidth uplink signal to the air interface device under test.
11. The system of claim 10 wherein the uplink signal generator is configured to generate long term evolution (LTE) or LTE advanced uplink signals.
12. The system of claim 10 wherein the uplink signal generator is configured to generate uplink reference signals, control channel signals, and data channel signals.
13. The system of claim 10 wherein the per-UE Doppler shifters are configured to apply Doppler shifts to the reference signals on a per-UE basis.
14. The system of claim 10 wherein the per-UE Doppler shifters are configured to apply the per-UE Doppler shifts to simulate a Doppler shift for a UE moving towards a stationary device under test.
15. The system of claim 10 wherein the per-UE Doppler shifters are configured to apply the per-UE Doppler shifts to simulate a Doppler shift for a UE moving away from a stationary device under test.
16. The system of claim 10 wherein the per-UE Doppler shifters are configured to apply Doppler shifts that simulate UEs traveling at different speeds with respect to the air interface device under test.
17. The system of claim 10 wherein the per-UE Doppler shifters are configured to apply Doppler shifts that simulate UEs traveling in different directions with respect to the air interface device under test.
18. The system of claim 10 wherein the air interface device under test comprises an evolved Node B (e-Node B).
19. A non-transitory computer readable medium having stored thereon executable instructions that when executed by the processor of a computer control the computer to perform steps comprising:
at a network equipment test device:
generating uplink signals including per user equipment (per-UE) time domain uplink signals to be transmitted from plural simulated UEs to an air interface device under test;
applying per-UE Doppler shifts to the per-UE time domain uplink signals, wherein applying per-UE Doppler shifts includes applying different Doppler shifts to at least some of the per-UE time domain uplink signals, wherein applying per-UE Doppler shifts includes utilizing a plurality of per UE Doppler in the network equipment test device that apply Doppler shifts to the per-UE time domain uplink signals;
performing discrete Fourier transformation and subcarrier mapping of the per-UE time domain, Doppler shifted uplink signals to produce a frequency domain entire bandwidth uplink signal;
performing inverse fast Fourier transformation of the frequency domain entire bandwidth uplink signal to produce a time domain entire bandwidth uplink signal; and
transmitting the time domain entire bandwidth uplink signal to the air interface device under test.