wifi: Extend WifiPpdu to return the modulation class

src/wifi/model/wifi-ppdu.cc

@@ -449,6 +449,12 @@ WifiPpdu::IsMu (void) const
   return ((m_preamble == WIFI_PREAMBLE_VHT_MU) || (m_preamble == WIFI_PREAMBLE_HE_MU));
 }
 
+WifiModulationClass
+WifiPpdu::GetModulation (void) const
+{
+  return m_modulation;
+}
+
 void
 WifiPpdu::Print (std::ostream& os) const
 {

src/wifi/model/wifi-ppdu.h

@@ -102,6 +102,12 @@ public:
    */
   bool IsMu (void) const;
 
+  /**
+   * Get the modulation used for the PPDU.
+   * \return the modulation used for the PPDU
+   */
+  WifiModulationClass GetModulation (void) const;
+
   /**
    * \brief Print the PPDU contents.
    * \param os output stream in which the data should be printed.