Pilot strength measurement and multipath delay searcher for CDMA receiver
AssigneeEricsson Inc.
InventorsEssam Abdelfattah Sourour, Greg Bottomley, Rajaram Ramesh
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Abstract
A method and apparatus for evaluating signal strength of a channel received at a mobile station within a spread spectrum communication systems is disclosed. If the receiver at the mobile station receives a spread spectrum signal, a first sampling means converts the received signal into a first sample stream as a first sampling. A second sampling means converts the first sample stream into a second sample stream at a second sample rate, different from the first sample rate. The signal strength of a pilot channel is measured based upon the first and second sample streams.
Claims19
A method for evaluating a channel's signal strength at a mobile station comprising the steps of:
- receiving a signal;
- converting the received signal into a first sample stream according to a first sampling rate;
- converting the first sample stream into a second sample stream according to a second sampling rate, wherein the second sampling rate is different than the first sampling rate;
- generating a search window for the first sample stream using a sliding correlator;
- and
- measuring the signal strength of the second sample stream using the search window.
An apparatus for evaluating CDMA channel signal strength at a mobile station in a spread spectrum communications system, comprising:
- a receiver for receiving a signal;
- first sampling means for converting the received signal into a first sample stream according to a first sampling rate;
- second sampling means for converting the first sample stream into a second sample stream according to a second sampling rate, wherein the second sampling rate is different than the first sampling rate;
- a sliding correlator for generating a search window for the first sample stream;
- and
- a measurer for measuring the signal strength of the second sample stream using the search window.
A method for evaluating CDMA channel signal strength at a mobile station comprising the steps of:
- receiving a CDMA signal;
- converting the received CDMA signal into a first sample stream according to a first sampling rate;
- converting the first sample stream into a second sample stream according to a second sampling rate, wherein the second sampling rate is lower than the first sampling rate;
- selecting an optimal down sampling phase for the second sample stream;
- generating a search window for the first sample stream using a sliding correlator;
- measuring the CDMA signal strength of the second sample stream using the search window.
Dependencies are inferred from the claim text.