Patent ID: 6990059

Claim:
In a point to multipoint OFDM communication network, a method for operating a central access point, said method comprising: monitoring reception quality in a plurality of OFDM subchannels; designating a selected subchannel as below a quality threshold; and instructing a subscriber unit to not transmit payload data in said selected subchannel, wherein monitoring comprises: receiving a series of OFDM bursts from said subscriber unit; and measuring signal to noise ratio in said plurality of subchannels for each of said series of OFDM bursts, and wherein receiving comprises: receiving said series of OFDM bursts via a plurality of antennas; statistically characterizing noise and/or interference superimposed on data symbols of said OFDM bursts based on predefined training symbols within said OFDM bursts; and determining reception quality based on ratio of noise and/or interference to signal for said data symbols.