kaira.modulations.QPSKDemodulator

Inheritance diagram for QPSKDemodulator

class kaira.modulations.QPSKDemodulator(normalize: bool = True, *args, **kwargs)

Bases: BaseDemodulator

Quadrature Phase-Shift Keying (QPSK) demodulator.

Demodulates QPSK symbols back to bit pairs following Gray coding convention.

Methods

__init__	Initialize the QPSK demodulator.
forward	Demodulate QPSK symbols.
reset_state	Reset any stateful components.

Attributes

bits_per_symbol

Number of bits per symbol.

__init__(normalize: bool = True, *args, **kwargs) → None

Initialize the QPSK demodulator.

Parameters:

• normalize – If True, assume normalized constellation with unit energy

• *args – Variable length argument list.

• **kwargs – Arbitrary keyword arguments.

forward(y: Tensor, noise_var: float | Tensor | None = None, *args, **kwargs) → Tensor

Demodulate QPSK symbols.

Parameters:

• y – Received tensor of QPSK symbols

• noise_var – Noise variance for soft demodulation (optional)

• *args – Variable length argument list.

• **kwargs – Arbitrary keyword arguments.

Returns:

If noise_var is provided, returns LLRs; otherwise, returns hard bit decisions

property bits_per_symbol: int

Number of bits per symbol.

reset_state() → None

Reset any stateful components.

For demodulators with memory.