LTE 9种TM模式的中英文说明
别妄想泡我
855次浏览
2020年08月01日 07:57
最佳经验
本文由作者推荐
各行其事-骷髅的读音
2. TM2，发送分集模式：适合于小区边缘信道情况比较复杂，干扰较大的情况，有时候也用于高速的情况，分集能够提供分集增益.
3. TM3，开环空间分集：合适于终端（ue）高速移动的情况。
4. TM4，闭环空间分集：适合于信道条件较好的场合，用于提供高的数据率传输。
5. TM5，MU-MIMO传输模式：主要用来提高小区的容量。
6. TM6，Rank1的传输：主要适合于小区边缘的情况。
7. TM7，Port5的单流Beamforming模式：主要也是小区边缘，能够有效对抗干扰。
8. TM8，双流Beamforming模式：可以用于小区边缘也可以应用于其他场景。
9. TM9, 传输模式9是LTE-A中新增加的一种模式，可以支持最大到8层的传输，主要为了提升数据传输速率
TE Transmission Mode:
Transmission mode 1: Single-antenna transmission.
Transmission mode 2: Transmit diversity, SFBC(Space-Frequency Block Coding)based.
Transmission mode 3: Open-loop codebook-based precoding in the case of more than one layer, degraded to transmit diversity in the case of rank-one transmission. (SU-MIMO)
Transmission mode 4: Closed-loop codebook-based precoding. (SU-MIMO).
Transmission mode 5: Multi-user MIMO version of transmission mode 4 (up to max 2 users/layers).
Transmission mode 6: Special case of closed-loop codebook-based precoding limited to single layer transmission, also called beam-forming for single user.
Transmission mode 7: Release-8 non-codebook-based precoding supporting only single-layer transmission per UE, it is also called beam-forming here for single layer per UE.
Transmission mode 8: Release-9 non-codebook-based precoding supporting up to two layers per UE.
Transmission mode 9: Release-10 non-codebook-based precoding supporting up to eight layers per UE.
Codebook based mode means the precoding matrix can only be selected from known(predefined) cookbook.
Non-codebook based mode requests different demodulation/UE specific reference signals to be inserted in the allocated RBs of PDSCH before precoding and the precoding matrix is completely selected by randomly. This mode supports up to 8 transmission layers(ranks) per UE in Release10.
Closed-loop precoding is assumed that the network selects the precoder matrix based on feedback(CSI-PMI/RI) from the terminal.
Open-loop precoding does not rely on any detailed precoder recommendation being reported by the terminal and does not require any explicit network signaling of the actual precoder used for the downlink transmission. Instead, the precoder matrix is selected in a predefined and deterministic way known to the terminal in advance. One use of open-loop precoding is in high-mobility scenarios where accurate feedback is difficult to achieve due to the l******cy in the PMI reporting.