Method and apparatus with notched transmit frequency bins

A method of communicating between a first radio communication unit and a second radio communication unit, wherein said first radio communication unit and second radio communication unit are users of a signal spectrum, said method comprising:

• establishing a network wherein said first radio communication unit and said second radio communication unit communicate;
• receiving a signal at said first radio communication unit;
• determining from said received signal frequencies at which power levels are above a preset power threshold at said first radio communication unit;
• and
• transmitting from said first radio communication unit to said second communication unit a list of said frequencies having power levels above said preset threshold.

A method of communicating between a base station and a subscriber unit, wherein said base station and said subscriber unit are secondary users of a signal spectrum, said method comprising:

• establishing a network wherein said base station and said subscriber unit communicate;
• receiving a signal at said base station;
• determining from said received signal frequencies at which power levels are above a preset power threshold at said base station;
• transmitting from said base station to said subscriber unit a list of said frequencies at which said power levels are above said preset power threshold;
• receiving said list at said subscriber unit;
• setting a first notch in one of a set of frequency bins which corresponds to a frequency found in said list, at said subscriber unit;
• setting a second notch in one of said set of frequency bins which corresponds to a second frequency identified from a set of restricted frequencies;
• periodically scanning a transmission band of said subscriber unit for a frequency having signal energy levels above a preset signal energy level at said subscriber unit;
• setting a third notch in one of said set of frequency bins which corresponds to a third frequency having a signal energy level above said preset energy threshold;
• creating a time-domain signal from said set of frequency bins;
• and
• transmitting said time-domain signal from said subscriber unit to said base station using said transmission band.