HSUPA ( high speed uplink packet access)

HSUPA ( high speed uplink packet access) through the use of multi-code transmission based on Node, HARQ, B fast scheduling key technology, makes the single cell maximum uplink data throughput rate of 5.76Mbit / s, greatly enhancing the WCDMA uplink data service capacity and frequency spectrum utilization.

Similar to HSDPA, HSUPA introduced five new physical channel of E-DPDCH, E-DPCCH, E-AGCH, E-RGCH, E-HICH and two new MAC entity MAC-e and MAC-es, and packet scheduling function from RNC down to NodeB, NodeB based on the realization of fast packet scheduling, and through the hybrid automatic retransmission of HARQ, 2ms wireless short frame and multi-code transmission key technology, makes the uplink data throughput can be achieved the highest rate of 5.76Mbit / s, greatly improving the uplink data service capacity. WCDMA Rel5 HSDPA WCDMA downlink direction ( from the radio access network to a mobile terminal direction) for packet optimization and evolution. Similar to HSDPA, HSUPA is an uplink direction (from the mobile terminal to a radio access network direction) for packet optimization and evolution. HSUPA is the HSDPA, WCDMA standard is another important evolution. The use of HSUPA technology, the peak transmission rate of upstream user can increase 2-5 times, the HSUPA can also make cell uplink throughput than R99 WCDMA 20-50%.

HSUPA uses three main techniques

HSUPA uses three main techniques: physical mixed retransmission, based on Node B fast scheduling, and 2msTTI short frame transmission. Following these technologies are introduced.

The physical mixed retransmission

[ L1 (Fast) HARQ] : in WCDMA R99, a retransmission of a packet is determined by RNC under the control of the RLC retransmission completed. In AM mode, RLC retransmissions due to RLC and Iub signaling interface transmission and retransmission delay over 100ms. In the HSUPA defines a physical layer packet retransmission mechanism, data retransmission of the packet in mobile terminal and base station room directly, the base station received by the mobile terminal to send the packet will be transmitted to the mobile terminal via the air interface of ACK / NACK signaling, if the received data packet correct will send ACK signals. If the received data packet errors will send NACK signals, the mobile terminal through the ACK / NACK instructions, can be quickly resend the transmission error of the data packet. As a result of bypassing the Iub interface transmission, in 10msTTI, retransmission delay is shortened to 40ms. In the HSUPA physical mixed retransmission mechanism, used to the soft combining ( soft combing) and incremental redundancy ( Incremental Redundancy), improve the retransmission of the data packet transmission accuracy.

Based on the Node B quick dispatch

( NodeB Scheduling) in WCDMA R99, mobile terminal transmission rate scheduling by RNC control, mobile terminal available maximum transmission rate in DCH establishment determined by RNC, RNC according to cell load and mobile terminal channel status change flexibly control the mobile terminal transmission rate. Based on the Node B fast scheduling is the core idea of mobile terminal by the base station to control the data transmission rate and transmission time. The base station according to the cell load condition, the user channel quality and required transmission data to determine the current mobile terminal available maximum transmission rate. When the mobile terminal is hoping to use higher data rate transmission, the mobile terminal sends a request to the base station signal, base station according to the cell load situation and scheduling strategy determines whether to agree with the request of a mobile terminal. If the base station to mobile terminal request, the base station will send signaling to improve mobile terminal to the highest available transmission rate. When the mobile terminal is a period of time has no data to send, the base station will automatically reduce the mobile terminal to the highest available transmission rate. As a result of these scheduling signaling in the base station and the mobile terminal is transmitted directly, so Node B based on fast scheduling mechanism of the base station can flexibly and rapidly control area of the mobile terminal transmission rate, so that the wireless cyber source to more effectively serve the access burst data of the user, thereby increasing throughput effect.

2msTTI short frame transmission

2msTTI and 10 ms TTI : WCDMA DCH R99 uplink transmission time interval ( TTI) for 10ms, 20ms, 40ms, 80ms. In HSUPA, using 10msTTI to reduce transmission delay. Although HSUPA also introduced 2ms TTI transmission, further reduce transmission delay, but based on 2msTTI short frame transmission is not suitable to work in the border area.

HSUPA and HSDPA are the WCDMA system for packet service optimization, HSUPA uses some similar to HSDPA, but HSUPA is not HSDPA simple uplink counterpart, HSUPA technology used to take into account the uplink of its own characteristics, such as soft switching, power control, and UE PAR ( PAPR ) problem?? by HSDPA AMC and Gao Jie HSUPA modulation has not been adopted.