Methods and apparatus for sensing the presence of a transmission signal in a wireless channel

An apparatus operable for sensing the presence of a transmission signal type within a wireless channel in a wireless communication, the apparatus comprising:

• a memory storing instructions executable by a processor;
• and
• at least one processor configured to execute the instructions stored in the memory to:
• calculate a spectral density estimate of a signal on the wireless channel;
• compare a first test value derived from the calculated spectral density estimate to a first threshold, and make a preliminary determination of the presence of the transmission signal type if the first test value exceeds the first threshold;
• and
• sense the presence of the signal type after a preliminary determination of the presence of the signal type is made by determining that an observed spectral density of a prescribed signal added to the signal on the wireless channel matches a model estimate of the spectral density of the prescribed signal by at least a predetermined degree.

An apparatus operable for sensing the presence of a transmission signal type within a wireless channel in a wireless communication, the apparatus comprising:

• means for calculating a spectral density estimate of a signal on the wireless channel;
• means for comparing a first test value derived from the calculated spectral density estimate to a first threshold;
• means for making a preliminary determination of the presence of the transmission signal type if the first test value exceeds the first threshold;
• and
• means for sensing the presence of the signal type after a preliminary determination of the presence of the signal type is made by means for determining that an observed spectral density of a prescribed signal added to the signal on the wireless channel matches a model estimate of the spectral density of the prescribed signal by at least a predetermined degree.

A computer program product comprising:

• a non-transitory computer-readable medium comprising:
• code for causing a computer to calculate a spectral density estimate of a signal on the wireless channel;
• code for causing the computer to compare a first test value derived from the calculated spectral density estimate to a first threshold;
• code for causing the computer to make a preliminary determination of the presence of the transmission signal type if the first test value exceeds the first threshold;
• and
• code for causing the computer to sense the presence of the signal type after a preliminary determination of the presence of the signal type is made by determining that an observed spectral density of a prescribed signal added to the signal on the wireless channel matches a model estimate of the spectral density of the prescribed signal by at least a predetermined degree.