Paging/PCCH是否支持HARQ合并？

It requires at the minimum an new data indicator (NDI), a redundancy version(RV) and a HARQ process number to perform a HARQ combining for a transport block.

In Sect. 5.3.2.1 of TS36.321, it’s stated that “in case of BCCH a dedicated broadcast HARQ process is used”.
So is this “ broadcast HARQ process” also used for paging/PCCH?

Considering redundancy version, it is stated in Sect. 7.1.7.3 that the RV shall set to 0 when the DCI 1C is scrambled by P-RNTI, and that the RV is set according to SI window for DCI 1C scrambled by SI-RNTI, implying that Chase and IR combining are possible for SI-RNTI while only Chase combining is applicable for P-RNTI. For DCI 1A, eNodeB is able to set RV as needed.

For the HARQ process ID, there’s no “HARQ process number” field in DCI 1C, and for DCI 1A with P-RNTI, the “HARQ process number” field is reserved, as stated in TS36.212.

As for NDI, there’s no NDI field for DCI 1C. Though there’s NDI filed in DCI 1A, it is defined clearly that the NDI bit is reserved for P-RNTI in Sect. 5.3.3.1.3 of TS36.212. Since there’s no NDI for P-RNTI, with DCI 1C or 1A, it is not applicable for a HARQ combining for Paging.

In summary, RV is available for transport block for PCCH, but either of HARQ process ID and NDI is available for PCCH. So it is clear that HARQ combining is not applicable for Paging, under the framework of 3GPP specification.

As to system information broadcast/BCCH, HARQ process ID and NDI are also not available in the downlink control information, namely DCI 1C or 1A. However, an extra and special HARQ process is explicitly defined for BCCH in TS36.321, named broadcast HARQ process. Furthermore, the NDI for BCCH transport block is determined from the SI scheduling information. There extra settings make it possible to perform HARQ combining (even incremental redundancy!) for BCCH.

你这里所谓的PCCH是什么？ PBCH么？ paging和PBCH和MIB/SIB都是广播的，没有HARQ的概念，所以不需要做HARQ合并。

PBCH在其发送的连续4个Radio frame上传的是不同的RV版本，这四个对应的RV可以做合并

回复 2# 的帖子
PCCH不是一个基本概念么？其基本程度与PBCH相当。

另外，PBCH也没有所谓的4个RV版本做合并；4个RV版本做合并的是DBCH, 或者说SIB对应的PDSCH。在UMTS或者LTE里，只有TC才有RV之说；PBCH使用的是CC与重复码，与RV有何关系。

Paging是在PDSCH以随路信令形式发送，302上说的很明确，不支持HARQ。
- No PCH Hybrid ARQ, i.e. no higher-layer control of redundancy version.

回复 4# 的帖子
杰斐科童鞋，为什么你要把Paging叫做随路信令呢？人家独占对应的PDSCH，哪里随了。像AN, CQI等控制信息，与用户数据一起挤占PUSCH，那才叫随路信令。

另，兰州在楼顶只是更详细分析，各个逻辑信道对应的HARQ合并情况。而不是像302那样，一句话说完，懂的人继续懂，不明白的人继续不明白，是不是？

回复 3# 的帖子
你说的没错，标准里对RV版本的定义确实只是在传输信道上有。。我在这里说的PBCH四个TTI可以HARQ合并准确来说也不是HARQ合并。。 而是说，PBCH的四个TTI里的数据是一个turbo编码出来的，所以这四个TTI数据可以合并。这个过程跟HARQ合并的原理过程是一样的。。

回复 6# 的帖子
童鞋，你有木有看我的帖子啊。都说PBCH是CC码！不是TC。你再仔细看看3楼。

回复 7# 的帖子
不好意思，确实搞错了，PBCH确实是卷积码，不是Turbo码，不过对于译码里的能量合并的话，没有区别的。