Cyclic Redundancy Check Part-2

Duration: 4 min

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Module outline

  1. Quantitative Aptitude: Number System, Divisibility Rules, HCF LCM, Percentage, Ratio and Proportion (Ratios), Average, Profit and Loss, Simple Interest and Compound Interest, Mixture and Alligation, Partnership, Age Problems, Time and Work, Pipe and Cistern, Speed Time and Distance, Algebra, Arithmetic, Data Interpretation, Sequence and Series (Series), Logarithm, Powers and Exponents (Surds and Indices), Permutation and Combination, Probability, Speed Mathematics and Basic Mathematics, Trigonometry
  2. Logical Reasoning: Coding Decoding, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Seating Arrangements, Puzzle Solving (Puzzles), Data Arrangement, Syllogisms, Inequality, Data Sufficiency, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Venn Diagram, Logical Sequence Of Words, Calendar, Clock, Cubes & Dices, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning)
  3. Verbal Ability: Noun, Pronoun, Adjectives, Verb, Adverb, Tenses, Subject Verb Agreement (Verb Noun Agreement), Articles, Preposition, Conjunction, Modals, Determiner, Vocabulary, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Active Passive Voice (Voice), Direct and Indirect Speech, Sentence Construction
  4. Data Structures (Domain Test): Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  5. Algorithms (Domain Test):
  6. OOPs (Domain Test): Object Oriented Programming (OOPS)
  7. DBMS (Domain Test): Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, ORDBMS, Database Security & Authorization, Query Processing & Optimization, Enhanced Data Models, Data Warehousing & Mining, Big Data Systems, NoSQL
  8. SQL (Domain Test): SQL
  9. Operating Systems (Domain Test): Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS, Linux OS, Security, Distributed Systems, Virtual Machines
  10. Computer Networks (Domain Test): Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security, Cloud Computing and IoT, Cyber and Info Security
  11. Coding: Coding Questions by Yash Sir, C Programming by Yash Sir, Programming in C++, Java, Python for Placements by Yash Sir
  12. Written English Test: English Writing Ability
  13. Psychometric Test: Behavioral Assessment (Behavioral Competency Profiling) (Psychometric Test)
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This lecture segment introduces Cyclic Redundancy Check (CRC) as an error detection method using cyclic codes. The instructor explains the encoding process where a k-bit dataword is augmented with n-k zeros and divided by a generator polynomial using modulo-2 division. The remainder, consisting of n-k bits, is appended to the original dataword to form an n-bit codeword. The decoder receives this codeword and processes it through a checker identical to the generator, producing an n-k bit syndrome. If all syndrome bits are zero, the dataword is accepted; otherwise, it indicates errors and the codeword is discarded.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The lecture opens with a slide titled "Cyclic Redundancy Check" displaying block diagrams for Sender Encoder and Receiver Decoder. The instructor uses a pen to point at the dataword section showing input bits d3 d2 d1 d0 being processed by a generator to produce remainder bits r2 r1 r0. Bullet points explain augmenting the dataword with zeros and performing modulo-2 division to create a codeword. The text on screen identifies key components: Generator, Checker, and Decision logic. The presenter highlights that the quotient is discarded while only the remainder forms part of the final transmission, establishing the fundamental encoding mechanism.

  2. 2:00 – 3:49 02:00-03:49

    The instructor focuses on the decoding process and syndrome calculation. He circles the divisor size formula "n - k + 1" on screen and writes notes like "n-k=3" to illustrate the remainder length. The slide explains that the decoder receives a possibly corrupted codeword, feeding all n bits to a checker which is a replica of the generator. The remainder produced becomes an n-k bit syndrome fed to decision logic analyzer. If syndrome bits are all 0s, the leftmost k bits of codeword are accepted as error-free dataword; otherwise, it is discarded. This completes the CRC cycle from encoding through error detection.

The video demonstrates a complete CRC workflow starting with dataword augmentation and modulo-2 division encoding, followed by syndrome-based error detection at the receiver. Key technical elements include the generator polynomial for division, the n-k bit remainder appended to form codewords, and the checker circuit producing syndromes for validation. The instructor emphasizes that quotient is discarded during encoding while remainder becomes parity bits, and at decoding, zero syndromes indicate successful transmission. The visual progression moves from sender-side bit processing to receiver-side syndrome analysis, showing how cyclic codes enable reliable data transmission through systematic error checking mechanisms.

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