US 2008/0291985 A1 · AGILE SPECTRUM MONITORING IN A RADIO TRANSCEIVER

Abstract

The invention relates to a method and an apparatus for agile RF spectrum monitoring in a radio system with dynamic frequency access. It provides a spectrum monitor based on non-coherent heterodyne detection that utilizes a DDS signal generator to digitally generate a reference signal at a variable reference frequency for mixing with an input RF signal received from an RF antenna, a pass-band filter and a log amplifier for obtaining energy estimates at a monitored transmission frequency corresponding to the reference frequency. A processor is provided for adaptively selecting sets of monitored transmission frequencies, for controlling the DDS signal generator, and for processing obtained spectral energy estimates to assess spectral usage data.

Claims10

Dependent claims

A method of spectrum monitoring in a radio transceiver utilizing dynamic spectrum allocation for radio transmission, the method comprising the steps of:

(a) digitally synthesising a reference signal at a variable reference frequency corresponding to a monitored transmission frequency;
(b) mixing the digitally synthesized reference signal with an input radio signal received from an RF antenna to obtain a difference frequency signal;
(c) detecting the difference frequency signal at a detection frequency to obtain an estimate of the spectral energy of the input radio signal at the monitored transmission frequency;
and,
(d) determining the availability of the transmission frequency using the spectral energy value.

2 more elements

A spectrum monitor in a transceiver utilizing dynamic spectrum allocation and having a digital data processing and control (DDPC) section, an RF receiver section, and an RF transmitter section, the spectrum monitor comprising:

a) a direct digital synthesis (DDS) signal generator for digitally synthesising a reference signal at a variable reference frequency corresponding to a monitored transmission frequency;
b) an RF mixer connected to receive an input RF signal and the reference signal to output a mixed signal comprising a difference frequency signal;
c) a nonlinear device coupled to the RF mixer to receive the difference frequency signal for obtaining therefrom energy estimates for the input RF signal at the monitored transmission frequency in a selected measurement bandwidth;
d) an analogue to digital converter (ADC) for converting the detected signal into the digital domain;
and,
e) a spectrum processing module within the DDPC section, the spectrum processing module coupled to the DDS signal generator and the ADC for controlling the variable reference frequency and for storing and processing the energy estimates.

3 more elements

Dependencies are inferred from the claim text.

Agile spectrum monitoring in a radio transceiver

Life of this patent

Agile spectrum monitoring in a radio transceiver

Life of this patent

Abstract

Claims10