[Openlte-discuss] func prach_preamble_seq_gen in liblte_phy.cc

[Eugene B. <eug...@gm...>]

Hi!

variable N_neg_RA_shift declared as uint32
and expression  if(N_neg_RA_shift < 0) always false!

Maybe it's mistake ?

---------------------------------------------------------------
void prach_preamble_seq_gen(
...
    uint32 N_neg_RA_shift;
...
            // Determine N_RA_shift, d_start, N_RA_group, and N_neg_RA_shift
            if(d_u >= N_cs && d_u < phy_struct->prach_N_zc/3)
            {
                N_RA_shift     = d_u/N_cs;
                d_start        = 2*d_u + N_RA_shift*N_cs;
                N_RA_group     = phy_struct->prach_N_zc/d_start;
                N_neg_RA_shift = (phy_struct->prach_N_zc - 2*d_u -
N_RA_group*d_start)/N_cs;
                if(N_neg_RA_shift < 0)
                {
                    N_neg_RA_shift = 0;
                }
            }
            else
            {
                N_RA_shift     = (phy_struct->prach_N_zc - 2*d_u)/N_cs;
                d_start        = phy_struct->prach_N_zc - 2*d_u +
N_RA_shift*N_cs;
                N_RA_group     = d_u/d_start;
                N_neg_RA_shift = (d_u - N_RA_group*d_start)/N_cs;
                if(N_neg_RA_shift < 0)
                {
                    N_neg_RA_shift = 0;
                }
                if(N_neg_RA_shift > N_RA_shift)
                {
                    N_neg_RA_shift = N_RA_shift;
                }
            }

-- 


*Yours faithfully,*

*Eugene Bogush.*