Question

We want to transmit 800 characters/s, where each character is represented by its 7-bit ASCII codeword, followed by an eighth bit for error detection, per character, as in Problem 2.1. A multilevel PAM waveform with M = 16 levels is used. (a) What is the effective transmitted bit rate? (b) What is the symbol rate?

Answer 1

Answer:

Given that:

We want to transmit 800 characters/s, where each character is represented by its 7-bit ASCII codeword, followed by an eighth bit for error detection, per character, as in A multilevel PAM wavefrom with M=16 levels is used.

a) the effective transmitted bit rate is number of bit transmitted in unit time , bit/sec

it is given that we want to transmitt 800 character per sec, and each character has 7 bit ASCII code and eigth bit of error correction , ie a total of 8 bit in each character

So total bit per second = 800 x 8 =6400bits/sec

or 6.4 kbits/second

b)Symbol rate can be calculated as R = fslog₂(M) where fs is the symbol rate

R = 6400 bits/sec

M=16 levels

therefor symbol rate fs = 6400/log₂(16)=6400/4 = 1600

symbol rate =1600bit/sec