-
Member
Reputation: 165
CQI feedback periodicity
Hi All,
I was reading CQI reportting periodicity and its impact in LTE thuput trouble shooting. The concept I used from UMTS CQI. In huawei I modified feedback paramter. from 2 ms to 6 and 8 ms. I got some improvent in PS drop and accessibility. I want to correlate theory with observation. I chnged CQIFbCk and CQIFbCkforSHO for some cells of which some showed marked improvment. Can kindly someelse also trial it and share his findings ??
-
Post Thanks - 1 Thanks
-
2012-12-18 05:07 PM
# ADS
Circuit advertisement
-
Member
Reputation: 32
Re: CQI feedback periodicity
Hello,
we tried to increase the CQI feedback timer in our network to 8ms as well and it gave good improvement in the Accessibility & Retainability KPIs for the highly loaded sites, as the new setting will decrease the periodicity of reporting the CQI value by the UE & hence it will reduce the Uplink interference levels (RTWP level). However this setting will affect the CQI values, we monitored an significant degradation in the average reported CQI values by the UE.
-
Re: CQI feedback periodicity
Originally Posted by
romagdinio
Hello,
we tried to increase the CQI feedback timer in our network to 8ms as well and it gave good improvement in the Accessibility & Retainability KPIs for the highly loaded sites, as the new setting will decrease the periodicity of reporting the CQI value by the UE & hence it will reduce the Uplink interference levels (RTWP level). However this setting will affect the CQI values, we monitored an significant degradation in the average reported CQI values by the UE.
hi romagdinio, how much was the initial value, for some vendors like E******* its a system constant value ( default=10ms)..also d u use both periodic and aperiodic??
-
Re: CQI feedback periodicity
CQI (Channel Quality
Indicator)
This provides an indication of the downlink channel quality and effectively
identifies an optimum modulation and coding scheme for the eNB to use. There
are various coding options for the CQI; Figure 2-124 illustrates the main CQI
index.
-
Re: CQI feedback periodicity
CQI Index |
Modulation |
Code Rate x 1024 |
Efficiency |
0 |
out of range |
1 |
QPSK |
78 |
0.1523 |
2 |
QPSK |
120 |
0.2344 |
3 |
QPSK |
193 |
0.3770 |
4 |
QPSK |
308 |
0.6016 |
5 |
QPSK |
449 |
0.8770 |
6 |
QPSK |
602 |
1.1758 |
7 |
16QAM |
378 |
1.4766 |
8 |
16QAM |
490 |
1.9141 |
9 |
16QAM |
616 |
2.4063 |
10 |
64QAM |
466 |
2.7305 |
11 |
64QAM |
567 |
3.3223 |
12 |
64QAM |
666 |
3.9023 |
13 |
64QAM |
772 |
4.5234 |
14 |
64QAM |
873 |
5.1152 |
15 |
64QAM |
948 |
5.5547 |
-
Re: CQI feedback periodicity
Feedback Reporting
In order to optimize the system’s performance, the UE can provide various feedback information about the radio channel environment. LTE has various feedback reporting options which depend on the MIMO and eNB configuration. The reporting may consist of the following elements.
-
Member
Reputation: 32
Re: CQI feedback periodicity
Hello Minto,
The initial value was 2ms
-
Member
Reputation: 165
Re: CQI feedback periodicity
Moh700ah: Please donot post irrelevant info we all know what us CQI
romagdinio: I agree with your observation we also found improvment. However low reported CQI affected any throughput ??
-
Member
Reputation: 68
Re: CQI feedback periodicity
Originally Posted by
mobilink999
Hi All,
I was reading CQI reportting periodicity and its impact in LTE thuput trouble shooting. The concept I used from UMTS CQI. In huawei I modified feedback paramter. from 2 ms to 6 and 8 ms. I got some improvent in PS drop and accessibility. I want to correlate theory with observation. I chnged CQIFbCk and CQIFbCkforSHO for some cells of which some showed marked improvment. Can kindly someelse also trial it and share his findings ??
Can you please share the MML command? is it in the Inner CFGMML? as I'm not able to find it in the CFGMML and not able to generate the cell command in the offline Web LMT !!
-
Member
Reputation: 68
Re: CQI feedback periodicity
Originally Posted by
mobilink999
Hi All,
I was reading CQI reportting periodicity and its impact in LTE thuput trouble shooting. The concept I used from UMTS CQI. In huawei I modified feedback paramter. from 2 ms to 6 and 8 ms. I got some improvent in PS drop and accessibility. I want to correlate theory with observation. I chnged CQIFbCk and CQIFbCkforSHO for some cells of which some showed marked improvment. Can kindly someelse also trial it and share his findings ??
Originally Posted by
mobilink999
Hi All,
I was reading CQI reportting periodicity and its impact in LTE thuput trouble shooting. The concept I used from UMTS CQI. In huawei I modified feedback paramter. from 2 ms to 6 and 8 ms. I got some improvent in PS drop and accessibility. I want to correlate theory with observation. I chnged CQIFbCk and CQIFbCkforSHO for some cells of which some showed marked improvment. Can kindly someelse also trial it and share his findings ??
Can you please share the MML command? is it in the Inner CFGMML? as I'm not able to find it in the CFGMML and not able to generate the cell command in the offline Web LMT !!
Bookmarks