Patent ID: 7260054

Claim:
In a frame-based communications system utilizing orthogonal frequency division multiplexing (OFDM) and OFDM frames for multicarrier data transmission, each transmitted OFDM frame constructed from multiple time-domain OFDM symbols, one of the OFDM symbols being a known OFDM preamble, a method for measuring a signal to interference-plus-noise power ratio (SINR) for selected OFDM subchannel signals within the multicarrier data transmission to indicate channel quality and to adaptively adjust groupings of the OFDM subchannel signals to increase network capacity, the method comprising the steps of: computing a power spectral density (PSD) measurement vector S yy [n] from an OFDM preamble y[n] received in an nth OFDM frame; computing a PSD measurement vector S xx [n] from an OFDM preamble x[n] transmitted in the nth OFDM frame; computing a cross-PSD measurement vector S xy [n] between x[n] and y[n] for the nth OFDM frame; computing a PSD measurement vector S SIG [n] for the nth OFDM frame using S xx [n] and S xy [n]; computing a PSD measurement vector S IPN [n] for the nth OFDM frame using S yy [n] and S SIG [n]; specifying a subchannel grouping vector G[n] for the nth OFDM frame; computing a received signal power measurement vector P SIG [G[n]] for the subchannel grouping vector G[n] using S SIG [n]; computing a received IPN power measurement vector P IPN [G[n]] for the subchannel grouping vector G[n] using S IPN [n]; and computing a received SINR measurement vector ρ[G[n]] for the subchannel grouping vector G[n] using P SIG [G[n]] and P IPN [G[n]].