Physical Downlink Shared Channel (PDSCH)
This module implements the physical downlink shared channel. The complete physical layer chain at the transmitter and receiver is divided into upper physical layer chain (upperPhy) and lower physical layer chain (lowerPhy) as shown in figure-1. The upper physical layer consists of transport block processing, code-block processing, LDPC encoder/decoder, and, rate matching. On the other hand, the lower physical layer module implements modulation (symbol mapping), scrambling, layer mapping and resource mapping. It return the OFDM resource grid for sub-carrier/sub-band specific precoding/beamforming and other RF specific processing. These modules provides the high level APIs for the PDSCH chains.
PDSCH Transmitter
The details about the transmitter side of the PDSCH are provided in [3GPPTS38211pdsch], [3GPPTS38212pdsch], [3GPPTS38213pdsch] and, [3GPPTS38214pdsch]. The chain is bi-parted into upper physical layer and lower physical layer section to entertain both the link-level and system level simulations. The details of the APIs is provided in following sub-sections.
PDSCH Receiver
The receiver implements the complementary operations of transmitter side PDSCH chain. The PDSCH upper phy decoder implements the receiver side version of the PDSCH upper physical layer and same for lower physical layer as well.
PDSCH Components
The PDSCH chain, as shown in fig-1, consists of multiple small modules arranged sequentially. These modules provides the low level APIs for developing the complete PDSCH chain. The low level APIs has been design to provide the modular design and support the plug and play feature. This allows to research independently on each module and enhance the performance of the complete chain.
- Transport Block Size Computation
- Transport Block Processing
- Code Block Segmentation
- Low Density Parity Check Codes
- Rate Matching
- Code Block Concatenation
- References:
- [3GPPTS38211pdsch]
(3GPP TS 38.211 version 17.1.0 Release 17) 5G;NR;Physical channels and modulation.
[3GPPTS38212pdsch](3GPP TS 38.211 version 17.1.0 Release 17) 5G;NR;Physical channels and modulation.
[3GPPTS38213pdsch](3GPP TS 38.213 version 16.5.0 Release 16) 5G;NR;Physical layer procedures for control.
[3GPPTS38214pdsch](3GPP TS 38.214 version 17.0.0 Release 17) 5G;NR;Physical layer procedures for data.