TD-SCDMA Physical Layer Overview

This page provides an overview of the UTRA Physical Layer, specifically focusing on the TD-SCDMA Physical layer as per the TDD (Time Division Duplex) mode. The example presented is for a 1.28Mcps system, and the diagram illustrates the transport channel part.

As depicted in the figure below, the TD-SCDMA physical layer transmitter encompasses a series of modules that data from Layer 2 passes through. These modules include:

1. CRC and Tail bits addition
2. Transport block concatenation and code block segmentation
3. Channel Coding (CC/Turbo)
4. Radio frame equalization
5. Interleaving
6. Radio Frame Segmentation
7. Rate Matching
8. Multiplexing
9. Bit Scrambling
10. Physical channel mapping
11. Data modulation
12. Spreading
13. Complex scrambling
14. Pulse shaping(RRC)
15. IQ modulation
16. RF up conversion and transmission to the channel

Fig.1 TD-SCDMA Physical layer Transmitter

TD-SCDMA 3GPP Standard References

The following 3GPP Technical Specifications (TS) are relevant to TD-SCDMA:

• 3GPP TS 25.222 - multiplexing, channel coding and interleaving.
• 3GPP TS 25.223 - Spreading and modulation.
• 3GPP TS 25.224 - Physical layer procedures.
• 3GPP TS 25.225 - Physical layer measurements.

These documents can be downloaded from the following links:

• www.3gpp.org/ftp/specs/archive/25_series/
• www.quintillion.co.jp/3GPP/Specs/