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nrPDCCHDecode

Decode PDCCH modulation symbols

Since R2018b

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Syntax

dcicw = nrPDCCHDecode(sym,nid,nrnti)
dcicw = nrPDCCHDecode(sym,nid,nrnti,nVar)

Description

example

dcicw= nrPDCCHDecode(sym,nid,nrnti)returns the soft bits resulting from the inverse operation of the physical downlink control channel (PDCCH) processing specified in TS 38.211 Section 7.3.2[1]. The decoding consists of the QPSK demodulation ofsym, and descrambling with the scrambling identitynid. The argumentnrntispecifies the user equipment (UE).

dcicw= nrPDCCHDecode(sym,nid,nrnti,nVar)specifies the noise variance scaling factor of the soft bits in the PDCCH demodulation.

Examples

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Open Live Script

Specify a random sequence of binary values corresponding to a DCI codeword of 560 bits. Generate PDCCH modulation symbols by scrambling with the PDCCH demodulation reference signal (DMRS) scrambling identity. Specify the user equipment by using the cell radio network temporary identifier.

dcicw = randi([0 1],560,1); nid = 2^11;% pdcch-DMRS-ScramblingIDnrnti = 123;% C-RNTIsym = nrPDCCH(dcicw,nid,nrnti)
sym =280×1 complex0.7071 + 0.7071i 0.7071 + 0.7071i -0.7071 + 0.7071i 0.7071 + 0.7071i 0.7071 + 0.7071i 0.7071 - 0.7071i -0.7071 + 0.7071i -0.7071 + 0.7071i -0.7071 + 0.7071i -0.7071 - 0.7071i ⋮

Demodulate and compare the soft bits with the input codeword.

nVar = 0; rxdcicw = nrPDCCHDecode(sym,nid,nrnti,nVar); isequal(dcicw,rxdcicw<0)
ans =logical1

Input Arguments

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Received PDCCH modulation symbols, specified as a complex column vector.

Data Types:single|double
Complex Number Support:Yes

Scrambling identity, specified as an integer from 0 to 65,535. Specify withnidthe physical layer cell identity number, ranging from 0 to 1007, or higher layer parameterpdcch-DMRS-ScramblingID, ranging from 0 to 65,535. For more information on these values, see TS 38.211 Section 7.3.2.3 and 7.4.1.3.

Data Types:double

UE identifier, specified as an integer from 0 to 65,519.

  • Ifnidis the PDCCH DMRS scrambling identity,nrntiis the cell radio network temporary identifier (C-RNTI) in a UE-specific search space.

  • Ifnidis the physical layer cell identity,nrntiis0.

For more information, TS 38.211 Section 7.3.2.3 and 7.4.1.3.

Data Types:double

Noise variance, specified as a nonnegative numeric scalar. The soft bits are scaled with the variance of additive white Gaussian noise (AWGN). The default value corresponds to an SNR of 100 dB, assuming unit signal power.

Note

The default value assumes the decoder and coder are connected back-to-back, where the noise variance is zero. To avoid-Infor+Infvalues in the output, the function uses1e-10噪声方差作为默认值。获得美联社propriate results when the signal is transmitted through a noisy channel, adjust the noise variance accordingly.

Data Types:double

Output Arguments

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Approximate log-likelihood ratio (LLR) soft bits, returned as a column vector of real numbers.dcicwinherits the data type ofsym.

Data Types:double|single

References

[1]3GPP TS 38.211. “NR; Physical channels and modulation.”3rd Generation Partnership Project; Technical Specification Group Radio Access Network.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2018b

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See Also

Functions