Update README.md

Added Lesson 6

Author: GuitarsAI

README.md

@@ -111,6 +111,38 @@
     - The Complete Psycho-Acoustic Model
     - Physical Models of Hearing
 
+## 06 PQMF Filter Bank, MPEG-1 / MPEG-2 BC Audio :<br> [![NBViewer](https://badgen.net/badge/Launch/on%20NBViewer/blue?icon=terminal)](https://nbviewer.jupyter.org/github/GuitarsAI/AudioCodingTutorials/blob/master/AC_06_PQMF_FilterBank.ipynb)[![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/GuitarsAI/AudioCodingTutorials/master?filepath=AC_06_PQMF_FilterBank.ipynb)[![Google Colab](https://badgen.net/badge/Launch/on%20Google%20Colab/black?icon=terminal)](https://colab.research.google.com/github/GuitarsAI/AudioCodingTutorials/blob/master/AC_06_PQMF_FilterBank.ipynb)[![Youtube](https://badgen.net/badge/Launch/on%20YouTube/red?icon=terminal)](https://youtu.be/yiPMDqBT7qk)
+
+    - The Basic Paradigm of T/F Domain Audio Coding
+    - MPEG Audio Standardization Philosophy
+    - MPEG 1/2
+        - MPEG-1 Audio
+            - The main building blocks
+            - MPEG Audio - Short Description of the Layers
+            - Block Diagram MPEG-1 Layer 1
+            - Block diagram Layer-3
+    - Example for the Time/Frequency Resolution for the 2-Stage Layer III Coder
+    - MPEG - Layer-1, -2 and -3 Compression: Header
+    - The Pseudo-Quadrature-Mirror Filter Bank (PQMF)
+        - PQMF Definition
+        - PQMF Reformulation
+        - PQMF Design
+    - Python Example Optimization
+    - PQMF Optimization
+        - Optimization Function
+        - Python Example
+        - Unity Condition
+    - PQMF Polyphase Implementation
+    - Hybrid Filter Bank & Aliasing
+        - Problem of Aliasing in a Cascaded Filter Bank
+        - Aliasing Reduction Structure (MP3)
+    - MPEG Audio - Layer-3: Bitstream
+    - MPEG-1 Audio Decoder
+        - MPEG Audio – General Decoder Structure
+        - MPEG - Audio Decoder Process (1) Layer-3 Decoder flow chart
+        - MPEG - Audio Decoder Process Layer-3 Decoder Diagramm
+    - Annex: Abbreviations and Companies
+    
  # YouTube Playlist
  [![Youtube](https://badgen.net/badge/Launch/on%20YouTube/red?icon=terminal)](https://www.youtube.com/playlist?list=PL6QnpHKwdPYjRWkWLswWmxFrDmj6leRwh)