Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Q. Explain about Hamming error correcting code?
Richard Hamming at Bell Laboratories worked out this code. We will only introduce this code with help of an illustration for 4 bit data. Let's presume a 4 bit number b4, b3, b2, b1. In order to create a simple error detection code which detects error in one bit only we can just add an odd parity bit. Though if we want to find which bit is in error then we may have to employ parity bits for different combinations of these 4 bits in such a way that a bit error can be recognized uniquely. For illustration we can create four parity sets as below
Source Parity Destination Parity
b1, b2, b3 P1 D1
b2, b3, b4 P2 D2
b3, b4, b1 P3 D3
b1, b2, b3, b4 P4 D4
Now very interesting phenomenon can be noticed in above displayed parity pairs. Assume data bit b1 is in error on transmission then it will cause alteration in destination parity D1, D3, D4.
ERROR IN Cause change in Destination Parity
(One bit only)
b1 D1, D3, D4
b2 D1, D2, D4
b3 D1, D2, D3, D4
b4 D2, D3, D4
Figure: The error detection parity code mismatch
So by simply comparing parity bits of source and destination we can recognize that which of four bits is in error. This bit then can be complemented to eliminate error. Please note that even source parity bit can be in error on transmission but under assumption that just one bit (irrespective of data or parity) is in error it would be detected as just one destination parity would be different. What should be length of error detection code that detects error in one bit? Before responding this question we have to look in comparison logic of error detection. Error detection is done by comparing two ‘i’ bit error detection and correction codes fed to comparison logic bit by bit (see figure below). Let’s have comparison logic that produces a zero if compared bits are same or else it generates a one. Consequently if similar Position bits are similar then we obtained zero at that bit Position however if they are dissimilar that is this bit position may point to an error then this Particular bit position would be marked as one. This way a matching word is built. This matching word is ‘i’ bit long so can signify 2i values or combinations.
What are included in scope of Supply Chain Management Consultancy? Supply Chain Management Consultancy's scope is extensive, and classically includes as given here: a. Sales
In a national transmission system, the characteristic impedances of the 4-wire circuit and the 2-wire circuit are 1200 ? and 1000 ? respectively. The average phase velocity of the
What are the main features of UML Defined system structure for the object modelling Support for all different model organization Strong modelling for behaviour an
What is the difference between latches and flip-flops based designs Latches are level sensitive whether flip-flops are edge sensitive. So, latch based design and flop based des
What is Inheritance? Inheritance is the method of deriving a feature of super class into sub class. Every sub class inherits the attributes, operations and association of its s
what is complex instruction set computer and reduced complex instruction set computer
Let's attempt to answer a fundamental question: 'How does the Computer execute a Program?' Let's describe this with the help of an example from higher level language domain. Pr
Explain the differences between Paging and segmentation. Paging and segmentation P aging Segmentation Computer memory is separa
Optimum solution based on constraint problems: Whether depending on what solver you are using so there constraints are often expressed as relationships between variables as e.
With respect to security, which one is the better choice? .Net or J2EE? Explain? As per majority programmers .NET is the best one which have single vendor compare to, the
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd