Q. What do you mean by Source Encoding?

After the quantization of message samples, the digital system will then code each quantized sample into a sequence of binary digits (bits) 0 and 1. Using the natural binary code is a simple approach. For a code with Nb bits, integers N (from 0 to 2^Nb - 1) are represented by a sequence of digits, b_N ,b_{N -1},...,b₂,b₁, such that

Note that b₁ is known as the least signi?cant bit (LSB), and b_Nb as the most signi?cant bit (MSB).

Since a natural binary code of Nb bits can encode Lb = 2^Nb levels, it follows that

L ≤ L_b= 2^Nb

if L levels span the message variations. For example, in Figure (b), N_b = 3 and L = 8; the binary code word 010 represents 0(2^3-1) + 1(2¹) + 0(2⁰) = 2 V, and 110 represents 1(2^3-1) + 1(2¹) + 0(2⁰) = 6 V. Thus, binary code words with N_b = 3 are shown in Figure (b).