In a particular phase modulation system, each symbol is able to represent 4 bits. What sort of PSK is being used?
To determine the type of phase shift keying (PSK) being used in a phase modulation system where each symbol represents 4 bits, we need to consider the relationship between the number of bits represented per symbol and the number of distinct phases used.
In PSK, the number of bits represented per symbol is directly related to the number of distinct phases used. This relationship is given by the formula:
Number of distinct phases = 2^(Number of bits represented per symbol)
Given that each symbol represents 4 bits in the system, we can calculate the number of distinct phases as follows:
Number of distinct phases = 2^4 = 16
Now, let's identify the type of PSK based on the number of distinct phases:
- BPSK (Binary Phase Shift Keying) uses 2 distinct phases (2^1 = 2).
- QPSK (Quadrature Phase Shift Keying) uses 4 distinct phases (2^2 = 4).
- 8PSK uses 8 distinct phases (2^3 = 8).
- 16PSK uses 16 distinct phases (2^4 = 16).
Since the number of distinct phases in this system is 16, the type of PSK being used is 16PSK.