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C 2 . log<br />

2(<br />

1<br />

)<br />

<br />

2(<br />

1<br />

)<br />

<br />

Simplifying you get,<br />

1 1 <br />

. log<br />

2(<br />

1<br />

)<br />

<br />

2(<br />

1<br />

)<br />

<br />

<br />

1<br />

log 2<br />

2(<br />

1<br />

)<br />

<br />

<br />

<br />

C = log [2 (1+)] – log <br />

or<br />

2(<br />

1<br />

)<br />

<br />

C = log2 <br />

<br />

Remember, = 2 and<br />

= - (p log p + q log q)<br />

What are the extreme values of p?<br />

Case – I: Say p = 1<br />

What does this case correspond to?<br />

What is C for this case/<br />

Note: = 0, = 2 0 = 1<br />

2( 1<br />

1)<br />

<br />

C log2 <br />

log<br />

1 <br />

<br />

2<br />

[ 4]<br />

If rs = 1/sec, C = 2 bits/sec.<br />

Can this case be thought of in practice?<br />

1<br />

Case – II: p =<br />

2<br />

bits/sec. -----(13)<br />

<br />

2 bits / sym.<br />

1 1 1 <br />

Now, = – log log 1<br />

2 2 2 <br />

= 2 = 2<br />

2( 2 1)<br />

<br />

log<br />

<br />

log 2 [ 3]<br />

1.<br />

585 bits / sec.<br />

2

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