Collision detection using a multiple symbol noncoherent soft output detector
First Claim
1. A receiver system for detecting collisions in received signals, comprising:
- a plurality of receivers, each configured to receive and sample a phase modulated input signal; and
a plurality of multiple symbol noncoherent soft output detectors, each configured to receive the sampled input signal from a receiver of the plurality of receivers and to generate a soft metric indicative of the reliability of a detected symbol based upon observations over multiple symbols;
a combiner configured to select from the soft metrics generated by the plurality of multiple symbol noncoherent soft output detectors; and
a collision detector configured to calculate a decision metric from the plurality of soft metrics selected by the combiner and to detect a collision when the decision metric satisfies a predetermined criterion.
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Abstract
Systems and methods for detecting collisions in radio frequency tags in accordance with embodiments of the invention are disclosed. In one embodiment, a receiver system includes a receiver configured to receive and sample a phase modulated input signal, and a multiple symbol noncoherent soft output detector configured to receive the sampled input signal and to generate a soft metric indicative of the reliability of a detected symbol based upon observations over multiple symbols, a collision detector configured to calculate a decision metric from a set of soft metrics generated by the multiple symbol noncoherent soft output detector and detect a collision when the decision metric satisfies a predetermined criterion.
54 Citations
20 Claims
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1. A receiver system for detecting collisions in received signals, comprising:
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a plurality of receivers, each configured to receive and sample a phase modulated input signal; and a plurality of multiple symbol noncoherent soft output detectors, each configured to receive the sampled input signal from a receiver of the plurality of receivers and to generate a soft metric indicative of the reliability of a detected symbol based upon observations over multiple symbols; a combiner configured to select from the soft metrics generated by the plurality of multiple symbol noncoherent soft output detectors; and a collision detector configured to calculate a decision metric from the plurality of soft metrics selected by the combiner and to detect a collision when the decision metric satisfies a predetermined criterion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method for detecting collisions in received radio frequency transmissions, the method comprising:
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receiving and sampling a phase modulated input signal to produce symbol samples at each of a plurality of receivers; combining symbol samples to produce symbol observations using each of the plurality of receivers; generating a soft metric indicative of the reliability of a detected symbol based upon symbol observations over multiple symbols using each of the plurality of receivers; selecting from the soft metrics generated by the plurality of receivers; calculating a decision metric from the selected soft metrics; and detecting a collision in received radio frequency transmissions when the calculated decision metric satisfies a predetermined criterion. - View Dependent Claims (19, 20)
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Specification