Abstract: A tone detector is disclosed that is realizable in digital embodiment on a single integrated circuit die and does not require external components, such as a discrete capacitor. An input connects to a comparator, which in turn connects to one or more edge detectors and a flip flop. The edge detector outputs a pulse responsive to a detected edge. A counter is reset by the pulses from the edge detectors thereby preventing the counter from reaching a maximum value, which would otherwise be output from the counter and provided to a flip flop to clock in the comparator output at the D input to the flip flop. In operation, the comparator generates a rail to rail signal responsive to a received tone, which in turn is clocked through the flip flop as a logic high output indicating presence of a tone.

Abstract: An apparatus and a method for detecting the energy of a tone signal. A pre-process unit takes absolute values of transmitted samples and outputs the values to a delay unit for delaying the transmitted samples according to a predetermined delay interval. An operation unit subtracts the value calculated by multiplying the magnitudes of the samples transmitted before and after the burst detection from the square value of the magnitude of the sample at the time of burst detection among the delayed transmitted samples. A detection unit detects the burst by confirming whether peaks corresponding to the number of the samples transmitted before the sample of the burst detection are detected by a signal of an value input from the operation unit. Therefore, the present invention can reduce a probability of a false alarm caused by an impulse error and burst errors and thus perform stable burst detection.

Abstract: Circuitry for detecting tonal signals, each of which has a particular nature in the frequency or time domain, while distinguishing them from each other. A rough frequency analyzer roughly analyzes an input signal in an entire frequency band with lower accuracy in the frequency or time domain, thereby roughly distinguishing the tonal signals. Detectors, each of which is associated with a subband occupied by a particular target tonal signal, detect the attribute of the power variation of the target tonal signal with respect to time with higher accuracy in the direction of the frequency or time domain to thereby finely identify the target tonal signal. A controller selectively enables and disables the detectors in accordance with the results from the detectors. One of the detectors is enabled which is selected under the control of the controller.

Abstract: Provided is a signal detector and method for spectrum analysis and for measuring power of one or more channels of an electrical or optical signal. Each channel may carry a unique modulation tone. A DSP (digital-signal processor) performs DFTs (discrete Fourier transforms) on the signal. Frequency bands of interest which contain a tone that requires detection are processed. Higher layers of coherent integrations are performed on bands which have not detected a tone with a resolution that is suitable for power measurement. The higher layers of coherent integrations are performed by collecting additional data and performing a coherent integration. Further higher layer coherent integrations are performed until all modulation tones have been detected with a suitable resolution or up to a maximum detection latency.

Abstract: An apparatus for determining energy threshold detection values for detecting at least one tone having a known frequency and duration in an input signal. The input signal is input over a period of time that is divided into frame portions including at least an initial frame portion and a last frame portion. An energy value is determined for the at least one tone during each frame portion. A set of control flag signals are set for the at least two frame portions based on the energy values being below a threshold value in previous frame portions and the presence of noise in previous frame portions. An offset into a data table is determined based on the control word, the offset being used to retrieve a scaling coefficient and an address of an energy value for the at least two frame portions from the data table.