Wednesday, 15 January 2025

Annual Reveiw : 2024

 This is the evaluation of the Year 2024 on the metrics I set out to achieve and my personal reflections.


Wednesday, 23 October 2024

Career Review

Where is my career going? What am I doing? Am i in the right direction ?

Tuesday, 6 August 2024

5G Wireless Standard Design Notes


Module 6 :  

Proportional Fair scheduling algorithms used in Base stations (Lower data rate users are artificially boosted to ensure they get access to the resources)


Module 7: 5G physical downlink shared channel (PDSCH) transmit chain– CRC generation

  • Min Transport Block size 1RB = 24 bits MCS0 max Transport size = 319784, 275RB MCS27 
  • A 24 bit CRC can detect upto and including 24 bit errors
  • An Example of 2 bit CRC calculation given
  • Physical layer starts with CRC and ends with CRC (38.212, section 5.1)
Module 8: 5G PDSCH transmit chain – code block segmentation – part I
Segment Size = 8448, + 24-bit CRC
   

LDPC Decoder/Encoder needs a higher number of bits for better coding gain i.,e it can perform better even with a low SNR. Larger the codeblock size, better will be the performance of the decoder. In the above pic example the SNR needed for 8448 bits is lower compared to SNR needed to decode 2848 bits, i.e., we are penalizing the guy with lower codeblock. BLER is limited by the smallest transport size.

On the other hand, a high number of bits (Segment size) can lead to a higher decoding implementation complexity.

Module 9: 5G PDSCH transmit chain – LDPC coding


In the u matrix, 2 means the colums of I need to be shifted by 2, 3 means colums of I need to be shifted by 3 etc., This is done so that we dont need to store entire H matrix (savings in space in systems). Instead given a U and a I and size, we can generate a H matrix.
5G PDSCH supports 2 base graphs
  1.     Base Graph 1 optimized for large information block size and high code rates
    1. max code rate 8/9 min code rate 1/3
  2. Base Graph 2 optimized for small information block size and low code rates.
    1. Lowest code rate is 1/5
Base Graph 2 has lower decoding complexity.
Kb - The number of columns in Systematic matrix is fixed. implementation constraint. therfore the number of rows = Information bits (i.e., 8448) /22 = 384. so summarize we ll have a 384 X 22 matrix.

Module 10: 5G PDSCH transmit chain – code block segmentation – part II















Friday, 26 April 2024

Career Tips - from Trip to Irvine

 This list is the collection of all of my discussions with many Colleagues at Irvine and the key things/wisdom that I got to learn and the things that I wish to remember & use it for life. 

Discussions with Girish basruru, Ben Hui, Eddy Soethja, Trinh Nguyen, Diep Nguyen

Lessons learnt from my stay in Irvine

 Lessons learnt from my stay in Irvine.

The general way of life as I saw it. The way how people go about their lives. My interactions with everybody - personal values of people at work, professionalism at work, random people on the streets, hotel staff, cleaning staff, people at tourist places, people at stores etc.,

Trip to Irvine

 My memiors of my work trip to Irvine. 

What are some of the memories of the places that I happened to like during my stay in Irvine. 

Wednesday, 17 April 2024

Life Goals - Evaluations

The past few weeks have given me some time to reflect & refine about my life goals. The stuff which would make me/us proud of if we were to accomplish this. This in a way also reflects the state of my mind or my journey as I envision at this point in time. Nevertheless as they say "Every man can only accomplish what he can set out to" . So these are the lists


Half Yearly Evaluations :



Life Financial Goals : Fixed and Freezed