Receiver filtering out both systematic pulse noise and random noise
First Claim
1. A receiver for receiving and detecting tone signals in a noisy environment, where the amplitude of impulse noise exceeds the amplitude of the received signal, comprising:
- an amplitude limiting section for excluding noise above a predetermined amplitude;
a commutating filter section coupled to said amplitude limiting section, for generating a plurality of voltages indicative of a received signal within the passband of the filter section;
peak detection means, coupled to said commutating filter, for selecting the one of said voltages having the largest amplitude; and
threshold detecting means, coupled to said peak detecting means, for producing an output signal when said selected voltage exceeds a predetermined threshold to indicate the presence of a received tone.
0 Assignments
0 Petitions
Accused Products
Abstract
A continuous wave (c.w.) receiver is described comprising an amplitude limiting section, a commutating filter section, peak detecting means, and a threshold device. The receiver detects the presence or absence of an incoming signal over a very narrow, adjustable bandwidth. The limiting section clips the signal and noise at a predetermined amplitude and, in combination with the commutating filter, reduces the effect of noise, particularly impulse noise. The peak detector selects the highest output from the commutating filter and, in combination with the commutating filter, performs a pseudo-synchronization function when the received signal and an internal signal are not synchronized exactly.
21 Citations
15 Claims
-
1. A receiver for receiving and detecting tone signals in a noisy environment, where the amplitude of impulse noise exceeds the amplitude of the received signal, comprising:
-
an amplitude limiting section for excluding noise above a predetermined amplitude; a commutating filter section coupled to said amplitude limiting section, for generating a plurality of voltages indicative of a received signal within the passband of the filter section; peak detection means, coupled to said commutating filter, for selecting the one of said voltages having the largest amplitude; and threshold detecting means, coupled to said peak detecting means, for producing an output signal when said selected voltage exceeds a predetermined threshold to indicate the presence of a received tone. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
Specification