A transmission diversity system with convolutional coding in time division duplex DS-SS

A transmission diversity system combined with convolutional coding is presented for time division duplex (TDD) direct sequence spread spectrum (DS-SS). In a TDD channel, the correlation between the up and down links is very high, so that we can use a transmission diversity technique for the forward link transmission. However, TDD systems are generally used for indoor systems because the correlation of the up and down links is low and the performance of the system degrades when the mobile station moves fast. In this case, the performance is not so much improved even though transmission diversity is utilized. To overcome the problem, we introduce convolutional coding to a TDD/DS-SS system and combine it with transmission diversity.