Methods and apparatus for selecting between multiple carriers based on signal energy measurements

A wireless terminal for use in a communication system, the wireless terminal comprising:

• means for receiving a signal in a first period of time, said signal including a plurality of signal tones, each signal tone corresponding to a different frequency;
• means for performing a time to frequency conversion on said received signal to generate a set of signal components corresponding to different signal tones in a first frequency band;
• means for determining the energy of each of a plurality of different signal components which correspond to different frequencies within said first frequency band to generate a set of per signal tone energy values, each per signal tone energy value corresponding to a different frequency;
• means for comparing the determined energy of each of said plurality of different signal components to a threshold energy level which is greater than the average per signal tone energy of said received signal to detect a signal component corresponding to a beacon signal;
• and
• means for determining if a handoff should be initiated to a network attachment point which transmitted a detected beacon signal and which uses a carrier frequency to transmit user data that is different from a carrier frequency in use by said wireless terminal to communicate with a current point of network attachment.

A computer readable medium embodying computer executable instructions for controlling a wireless terminal, the computer readable medium comprising:

• instructions for causing the wireless terminal to receive a first signal in a first frequency band, said first signal including a plurality of signal tones, each signal tone corresponding to a different frequency;
• instructions for causing the wireless terminal to perform a time to frequency conversion on said received signal to generate a set of signal components corresponding to different signal tones in the first frequency band;
• instructions for causing the wireless terminal to determine the energy of each of a plurality of different signal components which correspond to different signal tones within said first frequency band to generate a set of per signal tone energy values, each per signal tone energy value corresponding to a different frequency;
• instructions for causing the wireless terminal to detect, from the per tone energy value of said signal components, a signal component corresponding to a beacon signal;
• and
• instructions for causing the wireless terminal to determine, based on the frequency of the signal component detected to correspond to a beacon signal, a carrier frequency corresponding to said beacon signal.

A wireless terminal for use in a communication system, the wireless terminal comprising:

• a receiver for receiving a signal in a first period of time, said signal including a plurality of signal tones, each signal tone corresponding to a different frequency;
• a digital signal processing module for performing a time to frequency conversion on said received signal to generate a set of signal components corresponding to different signal tones in a first frequency band;
• a signal quality detection module for determining the energy of each of a plurality of different signal components which correspond to different frequencies within said first frequency band to generate a set of per signal tone energy values, each per signal tone energy value corresponding to a different frequency;
• a receiver controller module for comparing the determined energy of each of said plurality of different signal components to a threshold energy level which is greater than the average per signal tone energy of said received signal to detect a signal component corresponding to a beacon signal;
• and
• a carrier band selection module for determining if a handoff should be initiated to a network attachment point which transmitted a detected beacon signal and which uses a carrier frequency to transmit user data that is different from a carrier frequency in use by said wireless terminal to communicate with a current point of network attachment.