A new channel simulation method for the urban mobile radio communication is proposed based on the Aulin's mathematical model which is suitable for urban areas. The proposed method maintains advantage of jakes method which is readily implemented in hardware and simulates well various channel states, and solves the problem that measured power spectrum generated by Jakes method does not agree with practical power spectrum. It has been shown by simulation that good agreements between measured values generated by the proposed method and theoretical values for atucorrelation, level crossing rate(LCR), average duration of fades(ADF) and power spectrum are obtained and that this method can easily produce several independent fading signals. And a new stabilizing algorithm of fast transversal filter(FTF) which is known to exhibit a very unstable behavior, due basically to the acummulation of roundoff errors is proposed. In this paper, by representing specific quantities of the algorithm in two different ways, we define a mesure counting these difference as well as the roundoff errors. This measure is used to correct the variables of the algorithm at each time step in order to reduce the roundoff error. It has been shown that required amount of computation for the proposed algorithm is linearly increased as the order of equalizer and that stability is increased in computation with the other existing algorithm.