Expand description
Offset QPSK (Proximity-1, CCSDS 211.0). Offset Quadrature Phase Shift Keying (OQPSK)
OQPSK staggers the I and Q channels by half a symbol period, ensuring they never transition simultaneously. This reduces the maximum phase change per transition from 180° (QPSK) to 90°, yielding a more constant envelope. Used in Proximity-1 links (CCSDS 211.0).
The modulator outputs at 2× the QPSK symbol rate to properly represent the I/Q offset. The demodulator re-aligns the channels before computing LLRs.
Structs§
- Oqpsk
- OQPSK modulator/demodulator with configurable noise parameters.
Functions§
- demodulate_
oqpsk - Demodulates OQPSK symbols to soft-decision i16 LLRs.
- modulate_
oqpsk - Modulates packed bits to OQPSK at 2× the symbol rate.