[srslte-users] pdcch_file_test

Wed May 4 13:37:34 UTC 2016

I don't think it's an issue with release compatibility. That descrambling
code you are looking for is in file srslte/lib/phch/sequences.c line 60.

On Tue, 3 May 2016 at 03:50 amr adel <amr.adelnasr at gmail.com> wrote:

> Hi Ismael,
>
> I have another question
> I was looking into pdcch.c in the descrambling process
> I know that the descrambling sequence should depend on the sub-frame
> number and the cell-ID using the expression (c_init = floor(ns/2)*2^9 +
> cell-ID)
> Where is this accounted for in the codes ?
>
> Also, I have one more observation, we have known from the cellular
> provider in our province that they have LTE Rel-11 deployed. Will that be a
> problem since srs-LTE supports LTE Rel-8 ?
> I guess to force backward compatibility, LTE Rel-11 should support LTE
> Rel-8 as well. Am I right ?
>
> Thank you,
>
> On Mon, May 2, 2016 at 12:29 AM, amr adel <amr.adelnasr at gmail.com> wrote:
>
>> 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
>>
>>
>
>
> --
> Amr Abdelnasser
>
>
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