HSDPA UE categories and data rates
- an overview or summary of the HSDPA UE categories, their definitions and details including the HSDPA data rates.
The 3rd Generation Partnership Project (3GPP) has divided HSDPA UEs or mobile terminals into twelve categories. These HSDPA categories define the different characteristics including different HSDPA data rates.
These HSDPA categories are needed to cater for a number of implementations of the HSDPA standard. This allows for different levels of performance to be implemented including the maximum HSDPA data rate. The characteristics of the UE can then be easily communicated to the network which can then communicate with the UE in a suitable manner. Accordingly these HSDPA categories are widely used.
HSDPA category definitions
The different HSDPA categories are outlined inth e table below. From this it can be sent hat the overall raw data rate and hence the category is determined by a number of elements including the maximum number of HS-DSCH codes, TTI, block size, etc.
|HS-DSCH category||Max No of HS-DSCH codes||Min inter-TTI interval||HSDPA data rate (Mbps)||Transport block size||Max no soft bits||Supported mod schemes|
Additional information about the HSDPA categories and HSDPA data rates table:
- The maximum number of HS-DSCH codes is the number of multiplexed codes on the high-speed physical downlink shared channel (HS-PDSCH) that receive data.
- The minimum transmission time interval (TTI) is the time interval allocated to the mobile terminal for receiving data. There is a balance between a short TTI for providing adaptivity and while keeping the overhead to a minimum.
- The maximum buffer size for hybrid automatic repeat request (H-ARQ) is determined considering signals received prior to resend and resent signals; it is the maximum number of bits in the receive buffer after demodulation.
- Categories 1-10 support 16QAM (16 quadrature amplitude modulation) as well as QPSK (quadrature phase shift keying). Categories 11 and 12 only support QPSK.
By Ian Poole
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