| 摘要 |
An automatic gain control circuit (3) for use in a direct sequence spread spectrum receiver includes a discrimination unit (10) which generates a discrimination signal error from received in-phase and quadrature base-band signals, whilst a multiplication unit (16) multiplies the discrimination signal error by a first loop gain constant during signal acquisition and a second different loop gain constant during signal tracking. A recursive integrator (22) then acquires an integrated AGC value from the multiplied discrimination signal error. <??>By using two different values of loop gain, the circuit is able to alternate between a "fast mode" during signal acquisition, and a "slow track" mode during signal tracking. <IMAGE> |
