Patent ID: 7672405

Claim:
A method for controlling the signal gain of a MultiBand -Orthogonal Frequency Division Multiplexing (MB-OFDM) baseband receiver, the method comprising: correlating a preamble symbol of a signal with a predetermined base sequence of the preamble symbol to generate a matched sum; determining a symbol boundary of the signal by comparing a value derived from the matched sum with at least one threshold value, wherein the symbol boundary marks the start of a preamble symbol of the signal and lies in between a zero-padding section and a signal segment of the signal; measuring power of the signal segment of the signal according to the symbol boundary so that the zero-padding section of the signal is not measured, wherein the signal segment starts from the symbol boundary; determining a gain magnitude for amplifying the signal according to the power of the signal segment; and amplifying the signal according to the gain magnitude; wherein the signal includes an in-phase component and a quadrature component, the matched sum includes an in-phase matched sum and a quadrature matched sum respectively corresponding to the in-phase component and the quadrature component, and the correlating step comprises: delaying the in-phase component of the preamble symbol for 1 to n sampling periods to generate a plurality of delayed in-phase samples, wherein n is the sample number of the predetermined base sequence; delaying the quadrature component of the preamble symbol for 1 to n sampling periods to generate a plurality of delayed quadrature samples; multiplying the delayed in-phase samples with a corresponding sample of the predetermined base sequence to generate a plurality of in-phase correlated products; multiplying the delayed quadrature samples with a corresponding sample of the predetermined base sequence to generate a plurality of quadrature correlated products; summing the in-phase correlated products to generate the in-phase matched sum; and summing the quadrature correlated products to generate the quadrature matched sum.