초록 ▼

A CDMA modem includes a modem transmitter having: a code generator which provides an associated pilot code signal and which generates a plurality of message code signals: a spreading circuit which produces a spread-spectrum message signal by combining each of the information signals with a respectiv

A CDMA modem includes a modem transmitter having: a code generator which provides an associated pilot code signal and which generates a plurality of message code signals: a spreading circuit which produces a spread-spectrum message signal by combining each of the information signals with a respective one of the message code signals; and a global pilot code generator that provides a global pilot code signal to which the message code signals are synchronized. The CDMA modem also includes a modem receiver having an associated pilot code generator and a group of associated pilot code correlators for correlating code-phase delayed versions of the associated pilot signal with a receive CDM signal to produce a despread associated pilot signal. The code phase of the associated pilot signal is changed responsive to an acquisition signal value until a pilot signal is received. The associated pilot code tracking logic adjusts the associated pilot code signal in phase responsive to the acquisition signal so that the signal power level of the despread associated pilot code signal is maximized. Finally, the CDMA modem receiver includes a group of message signal acquisition circuits, each including a plurality of receive message signal correlators which correlate respective local received message code signal to the CDM signal to produce a respective despread received message signal.

대표청구항 ▼

[ The invention claimed is:] [3.] A pilot vector correlator apparatus for collecting signal power of a spread pilot channel of a received spread signal, the spread signal having a plurality of received multipath signal components and the spread pilot channel being spread by a predetermined spreading

[ The invention claimed is:] [3.] A pilot vector correlator apparatus for collecting signal power of a spread pilot channel of a received spread signal, the spread signal having a plurality of received multipath signal components and the spread pilot channel being spread by a predetermined spreading code sequence, to produce a pilot data value and to provide a plurality of multipath signal weighting values determined from the spread pilot channel; the apparatus comprising:local pilot code sequence generator means for generating a plurality of local code sequences, each of the local code sequences being a code phase-shifted version of the pilot spreading code sequence;a plurality of pilot spreading code correlators, each pilot spreading code correlator correlating a respective one of the local code sequences with the spread signal, each spreading code correlator comprising i) a multiplier which multiplies the spread signal by a respective one of the local code sequences to produce a correlated pilot signal value, and ii) accumulator means for accumulating the correlated signal for a predetermined period to produce a despread multipath pilot signal component having a respective carrier signal phase value;filter means including a plurality of lowpass filters, wherein each one of the plurality of despread multipath pilot signal components is applied to a respective one of the plurality of low pass filters to produce a respective one of the plurality of multipath signal weighting values, each multipath signal weighting value corresponding to a carrier signal phase value of the respective received multipath signal component;complex multiplier means for performing complex multiplication including a plurality of complex multipliers, each complex multiplier coupled to receive a respective one of the plurality of despread multipath pilot signal components and the respective multipath signal weighting value, wherein each multipath pilot signal component is multiplied by the respective weighting value to produce a respective phase rotated pilot signal component of a plurality of phase rotated pilot signal components having substantially equal carrier phase values; andd) combining means for combining the plurality of phase rotated pilot signal components to produce the pilot data value.