Reconfigurable outer block interleaving over correlated Rayleigh fading for 3GPP turbo coding

Turbo coding in correlated Rayleigh fading channels is improved by outer block interleaving, but with added complexity and delay. Choosing the wrong number of columns can increase the BER, so a reconfigurable block interleaver with column number optimised for different operating environments is useful. Simulation results are presented for the four block interleaver configurations specified for the 3GPP mobile standard in the case of correlated Rayleigh fading. Using different data frame lengths in various scenarios, the advantages of adapting to an optimum number of columns are demonstrated.