Method and system for estimating the doppler spread in radio mobile communication systems and computer program product therefor

摘要

The Doppler spread associated to a transmission channel with a gain represented by a random process, is estimated by transmitting on the channel a digital signal (DPCCH_I,Q), which comprises at least one pilot signal, which in turn comprises fields of known symbols, and estimating, on the basis of the pilot signal(DPCCH_I,Q), the channel so as to generate a signal indicating the aforesaid gain. There is then detected the zero-crossing rate (eta) of the aforesaid signal during a given time interval, and there is also estimated the signal-to-noise ratio (SNR) associated to the channel. The bandwidth (f_D) of the aforesaid random process is estimated according to a reference quantity (I_D⁽²⁾), which comprises: a first term ({circumflex over (eta)}²pi²), representing an estimate ({circumflex over (eta)}) of said zero-crossing rate (eta); and a second term $\left(\frac{I_N^{\left(2\right)}-{\widehat{\mathrm{eta}}}^2{\mathrm{pi}}^2{I}_N^{\left(0\right)}}{2\mathrm{SNR}}\right),$ which includes said signal-to-noise ratio of the channel.