A novel technique for high speed uplink data transmission in 3G systems

In 3G systems, the achievable peak data rates on the uplink are much smaller than the downlink data rates due to noise rise constraints resulting from the nonorthogonal nature of the CDMA uplink. In this paper, we present a new time-orthogonal approach called high-speed data burst transmission mode. The concept is based on slot-synchronized slot-orthogonal transmissions whereby high-speed data transmissions take place in slots orthogonal to the slots used for low data rate transmission and physical layer control signaling. Using this approach very high data rates are achieved during data burst transmission because the noise rise constraint is relaxed due to the orthogonal nature of the transmissions. The simulation results show that the uplink capacity of the proposed scheme is comparable to the downlink capacity thus making the system symmetrical.