Comparing BPSK, QPSK, 4PAM, 16QAM, 16PSK, 64QAM and 32PSK
I have written another article in DSPDesginLine.com. This article can be treated as the third post in the series aimed at understanding Shannon’s capacity equation.
For the first two posts in the series are:
1. Understanding Shannon’s capacity equation
2. Bounds on Communication based on Shannon’s capacity
The article summarizes the symbol error rate derivations in AWGN for modulation schemes like BPSK, QPSK, 4PAM, 16QAM, 16PSK, 64QAM and 32PSK.
Based on the knowledge of bandwidth requirements for each type of modulation scheme, the capacity in bits/seconds/Hz is listed. Further, using the knowledge that the symbol to noise ratio is
times the bit to noise ratio
, the symbol error rate vs Eb/No curves are plotted. Using symbol error rate versus Eb/No plots, the Eb/No required for achieving symbol error rate of
is identified. Upon having the capacity and Eb/No requirement, the requirements for BPSK, QPSK, 4PAM, 16QAM, 16PSK, 64QAM and 32PSK are mapped on to the Shannon’s capacity vs Eb/No curve.
Further, assuming Gray coded modulation mapping, each symbol error causes one bit out of bits to be in error. So, the relation between symbol error and bit error is,
.
Using this assumption, the Bit Error Rate (BER) for BPSK, QPSK, 4PAM, 16QAM, 16PSK, 64QAM and 32PSK are listed and the BER vs Eb/No curve plotted.
Hope this article serves as a nice overview of the various digital modulation schemes. Click here to read the full article in DSPDesignline.com
Please click here to SUBSCRIBE to newsletter and download the FREE e-Book on probability of error in AWGN. Thanks for visiting! Happy learning.
(No Ratings Yet)
Loading ...If you liked this post, you may leave a comment below, or subscribe to the RSS feed.
You may also find these posts relevant...
Comments
hello sir,i have a case where i encode a message with convolutional coder and puncture it , map it to 16 qam and in the receiver- demodulate it using hard decisions , depuncture and perform viterbi decoding. this was done with constraint lengths k=3,5,7 and corresponding generator polynomials (5,7) ; (23,35) and (171,133).i plotted the BER vs SNR curves (with SNR considered from 2 to 12).The performance of the configuration had improved as k increased. why is it so? plase reply sor
hello! Krishina how are you today? i would like you to ask a help concerning 64-QAM modulation technique. i was doing a matlab simulation for 64-QAM OFDM but i didn’t get the exact output, do you have a matlab script which is used to simulate performance(BER Vs SNR) of 64-QAM modulation technique. hope u will send it to me this afternoon.
Bye….
Thank you inadvance