Channel coding schemes

Low-Density Parity Check (LDPC) code is used for eMBB physical data channels in which polar codes are employed for eMBB physical control channels, as well as for the PBCH. These channel coding schemes provide better throughput and latency performance compared to what we have in legacy LTE. Note that channel coding for other use cases such as massive Machine Type Communications (mMTC) and Ultra-Reliable Low Latency Communications (URLLC) are not part of Release 15’s scope. So, let’s start.

Transport channel coding chains

The following figure represents the basic coding scheme for the downlink shared channel. The diagram is very similar to what we have in LTE. A CRC is attached to the transport block, it is segmented onto the code blocks, and then, additional CRSes are attached to each code block:

Figure 6.14 – Transport channel coding for the downlink shared channel

Then, LDPC coding is performed for each...