Method and apparatus for constant envelope modulation
Certain aspects of the present disclosure relate to a method for modulating single carrier signals using constant envelope 2-CPM modulation and quasi-constant envelope filtered continuously rotated pseudo-PSK modulation in a wireless communication system.
1. A method for communication, comprising:
encoding a binary data stream using one of a continuously rotated differential pseudo BPSK (πh 2 -DPBPSK) encoding and a continuously rotated generalized differential pseudo QPSK (πh 4 -GDPQPSK) encoding; and
filtering the encoded binary data stream to produce a quasi-constant envelope modulated signal.
2. The method of communication of claim 1 , wherein encoding the binary data stream comprises continuously rotating a differentially encoded and mapped data stream by a constant phase of ph 2 , wherein p is Pi, and h 2 is a modulation index; and
wherein the mapping is BPSK mapping, and wherein the modulation index h 2 =½.
3. The method of communication of claim 1 , wherein encoding the binary data stream comprises continuously rotating a differentially encoded and mapped data stream by a constant phase of ph 4 , wherein p is Pi, and h 4 is a modulation index; and
wherein the mapping is a QPSK mapping and wherein the modulation index h 4 =¼.