A method and apparatus of bit demultiplexing for a rate 1/3 convolutional encoder in a wireless communication system, the method comprising, receiving bits from the rate-1/3 convolutional encoder, demultiplexing the received bits by distributing the bits sequentially into 3 sequences denoted as V0, V1 and V2 such that the first bit is going to the V0 sequence, the second bit is going to the V1 sequence and the third bit is going to the V2 sequence and ordering the sequences such that V0 is the first sequence, V1 is the second sequence and V2 is the third sequence.