M-PSK Modulator Baseband
Modulate using M-ary phase shift keying
- Library:
Communications Toolbox / Modulation / Digital Baseband Modulation / PM
Communications Toolbox HDL Support / Modulation / PM
Description
The M-PSK Modulator Baseband block modulates an input signal using M-ary phase shift keying (PSK) and returns a complex baseband output. The modulation order, M, which is equivalent to the number of points in the signal constellation, is determined by the M-ary number parameter. The block accepts scalar or column vector input signals.
Ports
Input
Output
Parameters
Model Examples
Block Characteristics
More About
Algorithms
The block outputs a baseband signal by mapping input bits or integers to complex symbols according to the following:
This applies when a natural binary ordering is used. Another common mapping is Gray coding, which has the advantage that only one bit changes between adjacent constellation points. This results in better bit error rate performance. For 8-PSK modulation with Gray coding, the mapping between the input and output symbols is shown.
Input | Output |
---|---|
0 | 0 (000) |
1 | 1 (001) |
2 | 3 (011) |
3 | 2 (010) |
4 | 6 (110) |
5 | 7 (111) |
6 | 5 (101) |
7 | 4 (100) |
The corresponding constellation diagram follows.
When the input signal is composed of bits, the block accepts binary-valued inputs that represent integers. The block collects binary-valued signals into groups of log2(M) bits.
References
[1] Proakis, John G. Digital Communications. 4th ed. New York: McGraw Hill, 2001.