by admin | Jun 7, 2015 | sem3
History of Data Communications Human communication did not start from scratch. All living species need to communicate with others of their kind. The father apart they are, the more sophisticated are the modes of communication. Plants communicate with other plants via...
by admin | Jun 7, 2015 | sem3
Data Communications Data communications refers to the exchange of data between a source and a receiver. Data communication is said to be local if communicating devices are in the same building or a similarly restricted geographical area. The meanings of source and...
by admin | Jun 7, 2015 | sem3
Digital Communication System – Comparison DIGITAL COMMUNICATION SYSTEM – COMPARISON (ASK- FSK- PSK- QAM): S.No Parameter PSK DPSK QPSK QAM FSK ASK 1 Modulation of Phase Phase Phase Amplitude and Phase Frequency Amplitude 2 Equation of transmitted...
by admin | Jun 7, 2015 | sem3
Bandwidth Efficiency Spectral efficiency Spectral efficiency, spectrum efficiency or bandwidth efficiency refers to the information rate that can be transmitted over a given bandwidth in a specific communication system. It is a measure of how efficiently a limited...
by admin | Jun 7, 2015 | sem3
16 QAM 16-QUADRATURE AMPLITUDE MODULATION(16 QAM): Both amplitude and phase gets modulated. 4 bits encoded forming and producing 16 different outputa are possible. N = 4, M = 2N = 24 = 16 Therefore 16 output phases will be produced. 16 QAM transmitter: Each channel...
by admin | Jun 7, 2015 | sem3
8 QAM 8-QUADRATURE AMPLITUDE MODULATION(8-QAM): The amplitude gets changed in 8-QAM , and it is not a constant value. 3 bits encoded forming tribits and producing 8 different output phase. N = 3, M = 2N = 23 = 8 Therefore 8 output phases will be produced. 8-QAM...
