Changes between Version 17 and Version 18 of WARPLab/Examples/OFDM

Timestamp:

Nov 2, 2015, 3:52:14 PM (9 years ago)

Author:

chunter

Comment:

--

WARPLab/Examples/OFDM

@@ -93 +93 @@
  * Sampling Frequency Offset (SFO) - The temporal duration of a sample is slightly different at the receiver and transmitter due to different sampling clocks. Over the course of a reception, the relative sample periods will drift apart from one another. This manifests as larger phase error for the outer subcarriers.
 
-At the [https://warpproject.org/trac/browser/ResearchApps/PHY/WARPLAB/WARPLab7/M_Code_Examples/wl_example_siso_ofdm_txrx.m#L27 top of the script], there are three control variables that toggle three different recovery systems: {{{DO_APPLY_CFO_CORRECTION}}}, {{{DO_APPLY_PHASE_ERR_CORRECTION}}}, {{{DO_APPLY_SFO_CORRECTION}}}. In this section, we will explore what happens when different combinations of these recovery systems are enabled or disabled. For reference, here is an example output from the design when all three recovery systems are activated:
+At the [https://warpproject.org/trac/browser/ResearchApps/PHY/WARPLAB/WARPLab7/M_Code_Examples/wl_example_siso_ofdm_txrx.m#L27 top of the script], there are three control variables that toggle three different recovery systems: {{{DO_APPLY_CFO_CORRECTION}}}, {{{DO_APPLY_PHASE_ERR_CORRECTION}}}, {{{DO_APPLY_SFO_CORRECTION}}}. In this section, we will explore what happens when different combinations of these recovery systems are enabled or disabled. 
 
 === CFO Recovery: Enabled, Phase Error Recovery: Enabled, SFO Recovery: Enabled ===
 
-||  [[Image(Cy_PEy_Sy_phaseError.png,width=400)]][[BR]]Phase Error Estimates and SFO Recovery Matrix  ||  [[Image(Cy_PEy_Sy_constellations.png,width=400)]] [[BR]]Rx Constellation  ||  [[Image(Cy_PEy_Sy_evm.png,width=400)]] [[BR]]Error Vector Magnitude (EVM)[[BR]] and effective SNR  ||
+||  [[Image(Cy_PEy_Sy_phaseError.png,width=400)]][[BR]]1. Phase Error Estimates and SFO Recovery Matrix  ||  [[Image(Cy_PEy_Sy_constellations.png,width=400)]] [[BR]]2. Rx Constellation  ||  [[Image(Cy_PEy_Sy_evm.png,width=400)]] [[BR]]3. Error Vector Magnitude (EVM)[[BR]] and effective SNR  ||
+
+The above plots are provided for reference. They show an example of how the receiver performs when all three recovery systems are enabled.
+
+1. The "Phase Error Estimates" plot shows a nominal phase twist for each OFDM symbol over the course of the reception. The "SFO Recovery Matrix" shows a phase correction that increases for outer subcarriers over the course of the reception.
+2. The "Rx Constellation" plot shows each received symbol overlaid on each transmitted symbol.
+3. The "EVM and SNR" plot shows that EVM is small and has little dependence on OFDM symbol index or subcarrier index. Furthermore, the red line shows the effective SNR of the reception (calculated from the EVM values themselves). 
+
+=== CFO Recovery: Disable, Phase Error Recovery: Enabled, SFO Recovery: Enabled ===
+
+||  [[Image(Cn_PEy_Sy_phaseError.png,width=400)]][[BR]]1. Phase Error Estimates and SFO Recovery Matrix  ||  [[Image(Cn_PEy_Sy_constellations.png,width=400)]] [[BR]]2. Rx Constellation  ||  [[Image(Cn_PEy_Sy_evm.png,width=400)]] [[BR]]3. Error Vector Magnitude (EVM)[[BR]] and effective SNR  ||
+
 
 == Limitations ==