Method and converter for converting rectangular signals to phase signals
AssigneeMotorola, Inc.
InventorsHenry L. Kazecki, John Diehl, Steven H. Goode
Life of this patent
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Abstract
A rectangular to phase converter (201) includes a first converter circuit (201B) which limits signals to a predetermined level. A phase selector (259) selects a relative phase from the limited signals. According to one aspect of the invention, input rectangular coordinate signals are mapped to the first quadrant in a first quadrant mapping circuit (201A) before the first quadrant signals are limited and the relative phase signal is returned to the original quadrant by an original quadrant mapping circuit (260).
Claims40
A rectangular signal to phase signal converter having an input to receive input rectangular signals, the rectangular signal to phase signal converter comprising:
- a limit circuit coupled to the input to receive input rectangular signals therefrom and to generate corresponding rectangular limit signals, the limit circuit selectively increasing values of input rectangular signals which are below a predetermined threshold level;
- and
- a phase selector coupled to the limit circuit to receive rectangular limit signals output thereby, and to select a phase signal corresponding to the rectangular limit signals output by the limit circuit.
A rectangular signal to phase signal converter comprising:
- an input couple d to an RF signal source to receive an L-bit input rectangular signal pair, wherein L is the number of bits in each input rectangular signal;
- a limit circuit coupled to the input for converting the L-bit input rectangular signal pair to a P-bit limited rectangular coordinate signal pair, wherein P is the number of bits in each limited rectangular coordinate signal and P is less than L;
- a phase selector coupled to the limit circuit to convert the P-bit limited rectangular coordinate signal pair to an N-bit phase signal;
- and
- an output coupled to the phase selector to output the phase signal.
A method of converting rectangular signals to phase signals, comprising the steps of:
- inputting L bit rectangular coordinate signal pair into a circuit;
- selecting bits of the rectangular coordinate signals of the coordinate signal pair such that the most significant of the selected bits of at least one of the coordinate signals of the coordinate signal pair is a logic one, and outputting the selected bits as a limited rectangular coordinate signal pair;
- selecting a phase in a phase selector as a function of the limited rectangular coordinate signal pair;
- and
- outputting the selected phase signal.
A receiver comprising:
- an input coupled to a source of RF signals;
- a demodulator coupled to the input to receive RF signals therefrom and to output I and Q rectangular signal pairs;
- a rectangular signal to phase signal converter coupled to the demodulator to convert the I and Q rectangular signal pairs to phase signals, the rectangular signal to phase signal converter comprising,
- a limit circuit coupled to the demodulator to selectively convert I and Q rectangular signals output by the demodulator which are below a predetermined level to signal levels above the predetermined level, such that the magnitude of I and Q rectangular signals output by the limit circuit are above a minimal level;
- and
- a phase selector for converting the I and Q rectangular signals output by the second limit circuit into phase signals which are output by the rectangular signal to phase signal converter;
- and
- a signal processor coupled to the phase selector to process the phase signals and generating a receiver output signal responsive thereto.
Dependencies are inferred from the claim text.