CDMA system which uses pre-rotation before transmission
AssigneeInterDigital Technology Corporation
InventorJohn D. Kaewell
Life of this patent
Estimating the term…
Abstract
A digital spread spectrum communication system calculates phase and frequency error on a received signal from a communicating entity during a wireless communication and pre-corrects a signal for phase and frequency error prior to transmission to that entity.
Claims6
A method for reducing transmission errors in a CDMA communication system having at least two communication units, comprising:
- receiving at a first communication unit a CDMA communication signal sent from a second communication unit;
- analyzing said received signal for phase errors;
- correcting said received signal with a correction signal based upon said analysis;
- using said correction signal to pre-rotate a signal prior to transmission from said first communication unit to said second communication unit.
A method for reducing transmission errors in a CDMA communication system having at least two communication units, comprising:
- receiving at a first communication unit a CDMA communication signal sent from a second communication unit;
- analyzing said received signal for errors;
- generating a correction signal based upon said analysis;
- and
- correcting an information signal, including voice or data, with said correction signal prior to transmission of said information signal from said first communication unit to said second communication unit.
A CDMA communication system for reducing transmission errors during communications between at least two communication units, each communication unit comprising:
- a receiver for receiving a CDMA communication signal sent from another communication unit;
- an analyzer for analyzing said received signal for errors and for generating a correction signal;
- and
- a correction unit correcting said received signal with a correction signal based upon said analysis;
- a transmitter for using said correction signal to pre-correct a signal prior to transmission to another communication unit.
A communication station of a CDMA system having a plurality of communication stations which communicate with each other over a CDMA air interface using a plurality of channels and a pilot signal for carrier offset recovery during reception;
- each communication station including a receiver and a transmitter;
- the receiving comprising:
- an adaptive matched filter for receiving demodulated CDMA communication signals producing a filtered signal by using a weighting signal;
- a rake receiver for receiving demodulated CDMA communication signals and a pseudo-noise signal generated for a selected channel and producing a filter weighting signal;
- means for the filter weighting signal with a correction signal, said correction signal for producing the weighting signal used by said adaptive matched filter;
- at least one despreader coupled to said adaptive matched filter output for despreading said filtered signal using the pseudo-noise signal generator for said selected channel to produce a despread signal;
- and
- the transmitter comprising:
- a data input for providing an information signal;
- at least one spreader for spreading said information signal;
- a mixer for mixing the spread signal with said correction signal prior to upconversion and transmission;
- whereby a transmitted signal is pre-corrected with said correction signal prior to transmission.
Dependencies are inferred from the claim text.