Hi,
I’m reading the TDL channel model in the example NR NTN PDSCH Throughput and I have some questions about it, can you explain for me please:
(not my main question, but I am wondering) In the step "Obtain a precoding matrix (wtx) to use in the transmission of the first transport block"
[estChannelGrid,sampleTimes] = HelperNRNTNThroughput.getInitialChannelEstimate(…
carrier,simLocal.NumTransmitAntennas,channel,simLocal.DataType);
in that HelperNRNTNThroughput.getInitialChannelEstimate function, I saw the nrPerfectChannelEstimate function – this is what I am wondering, because I think we just can only estimate the channel, and this step is the estimation for the precoding, how can we do perfect channel estimation? – as I understand, nrPerfectChannelEstimate is the function that we can convert the channel in expression (carrier,pathGains,pathFilters) to the ChannelGrid expression, there is no estimation here.
I checked here and saw that the values of estChannelGrid are in range [0.5, 0.7].
In the step "Perform least squares channel estimation between the received grid and each transmission layer"
[estChannelGrid,noiseEst] = nrChannelEstimate(rxCarrier,rxGrid,…
refDMRSIndices,refDMRSSymbols,’CDMLengths’,pdsch.DMRS.CDMLengths);
I checked the values of estChannelGrid here and saw the values are in range 10^-6 x [3, 7.5].
I saw a line "Apply path loss to the signal" in the second step:
txWaveform = txWaveform*db2mag(-pl_dB(carrier.NSlot+1));
Plathloss here db2mag(-pl_dB(carrier.NSlot+1)) is 1.5678e-08
I want to generate the acurate (perfect) channel in this case, so I tried to multiply the estChannelGrid from nrPerfectChannelEstimate with db2mag(-pl_dB(carrier.NSlot+1)) but the results are in range 10^-9, not 10^-6 (to be near to the estimated channel). – So I am thinking this is not a correct approach to generate the accurate channel.
So my question is, how can I generate the perfect (accurate) channel, so I can compare the estimated channel and the accurate one?
Thank you so muchHi,
I’m reading the TDL channel model in the example NR NTN PDSCH Throughput and I have some questions about it, can you explain for me please:
(not my main question, but I am wondering) In the step "Obtain a precoding matrix (wtx) to use in the transmission of the first transport block"
[estChannelGrid,sampleTimes] = HelperNRNTNThroughput.getInitialChannelEstimate(…
carrier,simLocal.NumTransmitAntennas,channel,simLocal.DataType);
in that HelperNRNTNThroughput.getInitialChannelEstimate function, I saw the nrPerfectChannelEstimate function – this is what I am wondering, because I think we just can only estimate the channel, and this step is the estimation for the precoding, how can we do perfect channel estimation? – as I understand, nrPerfectChannelEstimate is the function that we can convert the channel in expression (carrier,pathGains,pathFilters) to the ChannelGrid expression, there is no estimation here.
I checked here and saw that the values of estChannelGrid are in range [0.5, 0.7].
In the step "Perform least squares channel estimation between the received grid and each transmission layer"
[estChannelGrid,noiseEst] = nrChannelEstimate(rxCarrier,rxGrid,…
refDMRSIndices,refDMRSSymbols,’CDMLengths’,pdsch.DMRS.CDMLengths);
I checked the values of estChannelGrid here and saw the values are in range 10^-6 x [3, 7.5].
I saw a line "Apply path loss to the signal" in the second step:
txWaveform = txWaveform*db2mag(-pl_dB(carrier.NSlot+1));
Plathloss here db2mag(-pl_dB(carrier.NSlot+1)) is 1.5678e-08
I want to generate the acurate (perfect) channel in this case, so I tried to multiply the estChannelGrid from nrPerfectChannelEstimate with db2mag(-pl_dB(carrier.NSlot+1)) but the results are in range 10^-9, not 10^-6 (to be near to the estimated channel). – So I am thinking this is not a correct approach to generate the accurate channel.
So my question is, how can I generate the perfect (accurate) channel, so I can compare the estimated channel and the accurate one?
Thank you so much Hi,
I’m reading the TDL channel model in the example NR NTN PDSCH Throughput and I have some questions about it, can you explain for me please:
(not my main question, but I am wondering) In the step "Obtain a precoding matrix (wtx) to use in the transmission of the first transport block"
[estChannelGrid,sampleTimes] = HelperNRNTNThroughput.getInitialChannelEstimate(…
carrier,simLocal.NumTransmitAntennas,channel,simLocal.DataType);
in that HelperNRNTNThroughput.getInitialChannelEstimate function, I saw the nrPerfectChannelEstimate function – this is what I am wondering, because I think we just can only estimate the channel, and this step is the estimation for the precoding, how can we do perfect channel estimation? – as I understand, nrPerfectChannelEstimate is the function that we can convert the channel in expression (carrier,pathGains,pathFilters) to the ChannelGrid expression, there is no estimation here.
I checked here and saw that the values of estChannelGrid are in range [0.5, 0.7].
In the step "Perform least squares channel estimation between the received grid and each transmission layer"
[estChannelGrid,noiseEst] = nrChannelEstimate(rxCarrier,rxGrid,…
refDMRSIndices,refDMRSSymbols,’CDMLengths’,pdsch.DMRS.CDMLengths);
I checked the values of estChannelGrid here and saw the values are in range 10^-6 x [3, 7.5].
I saw a line "Apply path loss to the signal" in the second step:
txWaveform = txWaveform*db2mag(-pl_dB(carrier.NSlot+1));
Plathloss here db2mag(-pl_dB(carrier.NSlot+1)) is 1.5678e-08
I want to generate the acurate (perfect) channel in this case, so I tried to multiply the estChannelGrid from nrPerfectChannelEstimate with db2mag(-pl_dB(carrier.NSlot+1)) but the results are in range 10^-9, not 10^-6 (to be near to the estimated channel). – So I am thinking this is not a correct approach to generate the accurate channel.
So my question is, how can I generate the perfect (accurate) channel, so I can compare the estimated channel and the accurate one?
Thank you so much ntn, channel estimation, tdl channel MATLAB Answers — New Questions

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