Patent ID: 6304592
Filing Date: 2001-10-16
Classification: H04B,H04L

Abstract:
A spread-spectrum-phase-locked-loop apparatus, for use as part of a spread-spectrum receiver on a received-spread-spectrum signal having a plurality of packets, each of said plurality of packets generated from spread-spectrum processing a header-symbol-sequence signal with a chip-sequence signal and from spread-spectrum processing a data-symbol-sequence signal with the chip-sequence signal, comprising:code means for generating a replica of the chip-sequence signal;in-phase-symbol-matched means, coupled to said code means, responsive to having an in-phase-symbol-impulse response set from a replica of the chip-sequence signal generated by said code means, for despreading from the received-spread-spectrum signal, an in-phase component of a packet from the plurality of packets as a despread-in-phase component of a header-symbol-sequence signal, and responsive to having the in-phase-symbol-impulse response set from the replica of the chip-sequence signal generated by said code means, for despreading from the received-spread-spectrum signal, an in-phase component of the packet as a despread-in-phase component of a data-symbol-sequence signal;quadrature-phase-symbol-matched means, coupled to said code means, responsive to having a quadrature-symbol-impulse response set from the replica of the chip-sequence signal generated by said code means, for despreading from the received-spread-spectrum signal, a quadrature-phase component of the packet as a despread-quadrature-phase component of a header-symbol-sequence signal, and responsive to having the quadrature-symbol-impulse response set from the replica of the chip-sequence signal generated by said code means, for despreading from the received-spread-spectrum signal, a quadrature-phase component of the packet as a despread-quadrature-phase component of the data-symbol-sequence signal;a voltage-controlled oscillator (VCO) for generating a VCO-sine signal and a VCO-cosine signal, with the VCO-cosine signal having a phase 90.degree. from the VCO-sine signal;first product means, coupled to said in-phase-symbol-matched means and to said voltage-controlled oscillator, for multiplying the despread-in-phase component of any of the header-symbol-sequence signal and the data-symbol-sequence signal, by the VCO-cosine signal thereby generating a first product signal;second product means, coupled to said in-phase-symbol-matched means and to said voltage-controlled oscillator, for multiplying the despread-in-phase component of any of the header-symbol-sequence signal and the data-symbol-sequence signal, by the VCO-sine signal thereby generating a second product signal;third product means, coupled to said quadrature-phase-symbol-matched means and to said voltage-controlled oscillator, for multiplying the despread-quadrature-phase component of any of the header-symbol-sequence signal and the data-symbol-sequence signal, by the VCO-sine signal, thereby generating a third product signal;fourth product means, coupled to said quadrature-phase-symbol-matched means and to said voltage-controlled oscillator, for multiplying the despread-quadrature-phase component of any of the header-symbol-sequence signal and the data-symbol-sequence signal, by the VCO-cosine signal, thereby generating a fourth product signal;first combining means, coupled to said first product means and to said third product means, for combining the first product signal with the third product signal, thereby generating a first combined signal;second combining means, coupled to said second product means and to said fourth product means, for combining the second product signal with the fourth product signal, thereby generating a second combining signal;fifth product means, coupled to said first combining means and to said second combining means, for multiplying the first combined signal by the second combined signal, thereby generating an error signal;a non linear device, coupled between said fifth product means and said voltage-controlled oscillator, for speeding up response in the spread-spectrum-phase-locked-loop apparatus; andwherein said voltage-controlled oscillator, responsive to the error signal, adjusts a level of the VCO-sine signal and a level of the VCO-cosine signal.