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.
Interrupts are signals which cause the CPU to suspend the currently executing program and transfer to a special program known as an interrupt handler. Interrupt handler determines
All AWT event listeners expand the java.util.EventListener interface.
Explain busy waiting semaphores. Weak, Busy-wait Semaphores: The simplest method to implement semaphores. Useful while critical sections last for a short time, or we
A* Search - artificial intelligence: A* search in the combines is the best parts of uniform cost search, namely the fact that it's optimal and complete, and the other best par
Ethernet 10 Base 2 is an example of network topology. (A) Bus (B) Ring (C) Star
How different are interface and abstract class in .Net? Abstract classes cannot be instantiated it can have or can't have abstract method basically known as must inherit as th
Before we take a detailed look about software languages, let us consider the role of computers in engineering. Computers are commonly used in the areas of 'Computer Aided Design /
Question: (a) In order to encourage the development mobile technologies, Europe has opted for standardisation. What is the rationale behind this? Provide concrete examples of h
Q. Explain use of parallel sections construct? This illustration explains use of parallel sections construct. Three functions, fun1, fun2, and fun3, all can be executed simulta
Before getting into the design the designer should go by the SRS prepared by the System Analyst. The main tasks of design are Architectural Design & Detailed Design. In Arch
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