2-9
BPSK Modulation
BPSK is a kind of phase modulation using a digital signal. Depending on carrier phase
difference, BPSK is expressed as 0 or 1. Data signal "0" is not phase shifted; data
signal "1" is phase shifted 180 degrees.
HLL H L
Carrier
Digital signal
BPSK modulated signal
BPSK modulator
Phase
change
by 180°
no phase
change
Phase
change
by 180°
Phase
change
by 180°
Figure 2-12 BPSK Modulation
Frame synchronization
Detects a unique word.
De-permuting
Demodulated signal is de-permuted and input to the interleave matrix.
De-interleaving
Reassembles the message in the interleave matrix.
Viterbi Decoding
Decodes the viterbi-encoded signal.
De-scrambling
Scrambled signal is decorded.
To Next Page
Loading...
