Field test results of space-time equalizers and delayed diversity transmission in central Tokyo area

Field test of space-time (ST) equalizers for combating intersymbol interference (ISI) at base stations, was conducted in microcell and macrocell environments in central Tokyo area. Test results indicate that the ST equalizers provide significantly better bit error rate (BER) than an array processor alone does, due to both space and path diversity while suppressing the long-delayed path. Furthermore, a delayed diversity transmission (DDT) in a small delay spread environment provides sufficient delay-spread and improves the BER of the ST equalizer.