Process and device for estimating the speed of movement of a mobile terminal, in particular a cellular mobile telephone capable of operating according to the UMTS standard

A process for estimating a speed of movement of a cellular telephone comprising:

• estimating fading of a transmission channel;
• performing an autocorrelation on the fading for providing a first autocorrelation result, the autocorrelation being performed over a duration corresponding to a minimum speed of movement of the cellular telephone that is to be estimated, the autocorrelation is a normalized autocorrelation of at least one fading coefficient, with the first autocorrelation result being a vector having a chosen length;
• calculating a plurality of reference autocorrelation results for a plurality of predetermined values of speed of movement of the cellular telephone, the plurality of reference autocorrelation results are calculated based upon a predetermined autocorrelation function performed on the fading, and wherein the plurality of reference autocorrelation results are also vectors having the same length resulting from a normalized autocorrelation of the at least one fading coefficient using the predetermined autocorrelation function;
• comparing the first autocorrelation result to the plurality of reference autocorrelation results;
• and
• estimating the speed of movement of the cellular telephone based upon the comparing.

A device for estimating a speed of movement of a mobile terminal operating in a wireless communication system and communicating with a base station via a transmission channel, said device comprising

• channel estimation means for estimating fading of the transmission channel;
• first autocorrelation means for performing an autocorrelation of the fading for obtaining a first autocorrelation result, the first autocorrelation means performing a normalized autocorrelation of at least one fading coefficient with the first autocorrelation result being a vector having a chosen length;
• a memory for storing a plurality of precalculated reference autocorrelation results for a plurality of predetermined values of speed of movement of the mobile terminal, the plurality of precalculated reference autocorrelation results being calculated based upon a predetermined autocorrelation function performed on the fading, the plurality of precalculated reference autocorrelation results are also vectors having the same length resulting from a normalized autocorrelation of the at least one fading coefficient using the predetermined autocorrelation function;
• comparison means for comparing the first autocorrelation result to the plurality of precalculated reference autocorrelation results;
• and
• speed estimation means for estimating the speed of movement of the mobile terminal based upon the comparing.

A mobile terminal comprising:

• an analog stage;
• and
• a digital stage connected to said analog stage for estimating a speed of movement of the cellular telephone by
• estimating fading of a transmission channel,
• performing an autocorrelation of the fading for obtaining a first autocorrelation result, the autocorrelation performing a normalized autocorrelation of at least one fading coefficient with the first autocorrelation result being a vector having a chosen length,
• comparing the first autocorrelation result to a plurality of precalculated reference autocorrelation results, the plurality of precalculated reference autocorrelation results being calculated based upon a predetermined autocorrelation function performed on the fading, the plurality of precalculated reference autocorrelation results are also vectors having the same length resulting from a normalized autocorrelation of the at least one fading coefficient using the predetermined autocorrelation function, and
• estimating the speed of movement of the mobile terminal based upon the comparing.

A process for estimating a speed of movement of a mobile terminal operating in a Code Division Multiple Access (CDMA) type wireless communication system and communicating with a base station via a multipath transmission channel, the process comprising:

• estimating fading for each path of the multipath transmission channel to obtain a plurality of fading coefficients;
• combining values of the plurality of fading coefficients, and weighting them by respective signal-to-noise ratios;
• performing an autocorrelation on the fading for providing a first autocorrelation result, the autocorrelation being performed over a duration corresponding to a minimum speed of movement of the mobile terminal that is to be estimated;
• calculating a plurality of reference autocorrelation results for a plurality of predetermined values of speed of movement of the mobile terminal, the calculating being based upon a predetermined autocorrelation function performed on the fading;
• comparing the first autocorrelation result to the plurality of reference autocorrelation results;
• and
• estimating the speed of movement of the mobile terminal based upon the comparing.