[srslte-users] pdcch_file_test

[amr adel]

Hi Ismael,

Yeah, I am using the latest version of srs-LTE
I was comparing the decoding results of both srs-LTE and openlte for a
certain sub-frame (the crc result) and they both gave different values !!
If you like I can send you the LTE signal file that I have to test it
yourself. It's around 25 MB (9 frames recorded at 30.72 MSps)
Thank you so much,

On Fri, Apr 29, 2016 at 2:44 AM, Ismael Gomez <
ismael.gomez at softwareradiosystems.com> wrote:

> HI Amr,
>
> Are you using the last version 1.2? In 1.1 there was a bug in PDCCH
> decoding for some cell IDs.
>
> Regarding the CFI, this program you are using is a test program, designed
> to test the functionality of a small part of the system. Therefore the CFI
> is assumed to be constant. What you can do it modify it to decode the CFI
> dynamically every subframe.
>
> cheers
>
> On Thu, 28 Apr 2016 at 05:12 amr adel <amr.adelnasr at gmail.com> wrote:
>
>> Hi Ismael,
>>
>> I have a problem with the pdcch_file_test
>>
>> I am trying to decode the dci1A message using SIRNTI
>> Using OpenLTE, I verified that this message exists on even frames ,
>> subframe 5
>> However, I failed when I used the pdcch_file_test
>>
>> I have an LTE signal with 30.72 MSps that is saved in a binary file, with
>> a total of 9 frames captured --> 90 sub-frames
>> I was able to run pbch_file_test and pcfich_file_test successfully with
>> that file (I verified the values with OpenLTE)
>>
>> Also, one more issue with pdcch_file_test is that it assumes constant cfi
>> value for all subframes which is not true. I tried modifying that in the
>> code so that it changes the cfi value with each sub-frame but the code
>> failed to decode any dci1A messages (crc does not pass i.e. crc != SIRNTI)
>>
>> Any ideas what could be wrong ??
>>
>> This is a sample output that I got (I have modified the way the output is
>> displayed for debugging purposes)
>>
>> ==============================================================
>>
>> [INFO]:  Reading 30720 samples from sub-frame 4 frame 2 with cfi value 1
>> Extracting LLRs: E: 1440, SF: 4, CFI: 1
>> [INFO]:  Initializing common search space for SI-RNTI
>> Common SS Candidate 0: nCCE: 0, L: 3
>> Common SS Candidate 1: nCCE: 8, L: 3
>> Common SS Candidate 2: nCCE: 0, L: 2
>> Common SS Candidate 3: nCCE: 4, L: 2
>> Common SS Candidate 4: nCCE: 8, L: 2
>> Common SS Candidate 5: nCCE: 12, L: 2
>> [INFO]:  Initiated 6 candidate(s) in the Common search space
>> Skipping DCI:  nCCE=0, L=3, msg_len=28, mean=0.317454 crc 0
>> Skipping DCI:  nCCE=8, L=3, msg_len=28, mean=0.356984 crc 0
>> Skipping DCI:  nCCE=0, L=2, msg_len=28, mean=0.328331 crc 0
>> Skipping DCI:  nCCE=4, L=2, msg_len=28, mean=0.306578 crc 0
>> Skipping DCI:  nCCE=8, L=2, msg_len=28, mean=0.369074 crc 0
>> Skipping DCI:  nCCE=12, L=2, msg_len=28, mean=0.344894 crc 0
>>
>>
>> [INFO]:  Reading 30720 samples from sub-frame 5 frame 2 with cfi value 1
>> Extracting LLRs: E: 1440, SF: 5, CFI: 1
>> [INFO]:  Initializing common search space for SI-RNTI
>> Common SS Candidate 0: nCCE: 0, L: 3
>> Common SS Candidate 1: nCCE: 8, L: 3
>> Common SS Candidate 2: nCCE: 0, L: 2
>> Common SS Candidate 3: nCCE: 4, L: 2
>> Common SS Candidate 4: nCCE: 8, L: 2
>> Common SS Candidate 5: nCCE: 12, L: 2
>> [INFO]:  Initiated 6 candidate(s) in the Common search space
>> Decoded DCI: nCCE=0, L=3, msg_len=28, mean=0.839736, crc_rem=0xa76c crc
>> 42860
>> Decoded DCI: nCCE=8, L=3, msg_len=28, mean=0.790758, crc_rem=0x490d crc
>> 18701
>> Decoded DCI: nCCE=0, L=2, msg_len=28, mean=0.885439, crc_rem=0x38a3 crc
>> 14499
>> Decoded DCI: nCCE=4, L=2, msg_len=28, mean=0.794033, crc_rem=0x35b1 crc
>> 13745
>> Decoded DCI: nCCE=8, L=2, msg_len=28, mean=0.751408, crc_rem=0xe973 crc
>> 59763
>> Decoded DCI: nCCE=12, L=2, msg_len=28, mean=0.830108, crc_rem=0x22d9 crc
>> 8921
>>
>>
>> [INFO]:  Reading 30720 samples from sub-frame 6 frame 2 with cfi value 1
>> Extracting LLRs: E: 1440, SF: 6, CFI: 1
>> [INFO]:  Initializing common search space for SI-RNTI
>> Common SS Candidate 0: nCCE: 0, L: 3
>> Common SS Candidate 1: nCCE: 8, L: 3
>> Common SS Candidate 2: nCCE: 0, L: 2
>> Common SS Candidate 3: nCCE: 4, L: 2
>> Common SS Candidate 4: nCCE: 8, L: 2
>> Common SS Candidate 5: nCCE: 12, L: 2
>> [INFO]:  Initiated 6 candidate(s) in the Common search space
>> Skipping DCI:  nCCE=0, L=3, msg_len=28, mean=0.417290 crc 0
>> Skipping DCI:  nCCE=8, L=3, msg_len=28, mean=0.400091 crc 0
>> Skipping DCI:  nCCE=0, L=2, msg_len=28, mean=0.427990 crc 0
>> Skipping DCI:  nCCE=4, L=2, msg_len=28, mean=0.406590 crc 0
>> Skipping DCI:  nCCE=8, L=2, msg_len=28, mean=0.374190 crc 0
>> Skipping DCI:  nCCE=12, L=2, msg_len=28, mean=0.425992 crc 0
>> ==============================================================
>>
>> On sub-frame 5, frame 2, Openlte indicated that there is a dci1A message
>> Thank you,
>>
>> --
>> Amr Abdelnasser
>>
>>


-- 
Amr Abdelnasser
Postdoctoral Fellow
Electrical and Computer Engineering Department
University of Manitoba, Canada
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