STRLCPY/wirelesscomm

Added lab for unit 4
Sundeep Rangan committed 3 years ago

4f705251

1 parent 2b0d1623

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readme.md

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57	57		* [Lecture videos](./unit04_coding/readme.md) and in-class exercises
58	58		* Demo: Uncoded BER on fading channel [[PDF]](./unit04_coding/demo_uncoded.pdf) [[Matlab Live]](./unit04_coding/demo_uncoded.mlx)
59	59		* Demo: Convolutional coding on a fading channel[[PDF]](./unit04_coding/demo_conv.pdf) [[Matlab Live]](./unit04_coding/demo_conv.mlx)
	60	+	* Lab: 5G NR Downlink Throughput with Fading and LDPC coding [[PDF]](./unit04_coding/lab_partial/labPdsch.pdf) [[Matlab Live]](./unit04_coding/lab_partial/labPdsch.mlx)
60	61		* Unit 5. MAC-Layer Concepts
61	62		* Unit 6. Channel Estimation and Equalization
62	63		* Unit 7. Multiple Antennas and Beamforming
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unit04_coding/lab_partial/FDChan.m

1	+	classdef FDChan < matlab.System
2	+	% Frequency-domain multipath channel
3	+	properties
4	+	% Configuration
5	+	carrierConfig; % Carrier configuration
6	+
7	+	% Path parameters
8	+	gain; % Path gain in dB
9	+	dly; % Delay of each path in seconds
10	+	aoaAz, aoaEl; % Angle of arrival of each path in degrees
11	+	fd; % Doppler shift for each path
12	+
13	+	rxVel = [30,0,0]'; % Mobile velocity vector in m/s
14	+	fc = 28e9; % Carrier freq in Hz
15	+
16	+	gainComplex; % Complex gain of each path
17	+
18	+	% SNR parameters
19	+	Etx = 1; % average energy per PDSCH symbol
20	+	EsN0Avg = 20; % Avg SNR per RX symbol in dB
21	+
22	+	% Symbol times
23	+	symStart; % symStart(i) = start of symbol i relative to subframe
24	+
25	+	end
26	+	methods
27	+	function obj = FDChan(carrierConfig, varargin)
28	+	% Constructor
29	+
30	+	% Save the carrier configuration
31	+	obj.carrierConfig = carrierConfig;
32	+
33	+
34	+	% Set parameters from constructor arguments
35	+	if nargin >= 1
36	+	obj.set(varargin{:});
37	+	end
38	+
39	+	% TODO: Create complex path gain for each path
40	+	% obj.gainComplex = ...
41	+
42	+	% TODO: Compute the Doppler shift for each path
43	+	% obj.fd = ...
44	+
45	+	% Compute unit vector in direction of each path
46	+
47	+	% TODO: Compute the vector of
48	+	% symbol times relative to the start of the subframe
49	+	% obj.symStart = ...
50	+
51	+	end
52	+
53	+
54	+	end
55	+	methods (Access = protected)
56	+
57	+
58	+	function [rxGrid, chanGrid, noiseVar] = stepImpl(obj, txGrid, sfNum, slotNum)
59	+	% Applies a frequency domain channel and noise
60	+	%
61	+	% Given the TX grid of OFDM REs, txGrid, the function
62	+	% * Computes the channel grid, chanGrid, given the
63	+	% subframe number, sfNum, and slotNum, slotNum.
64	+	% * Computes the noise variance per symbol, noiseVar,
65	+	% for a target SNR
66	+	% * Applies the channel and noise to create the RX grid
67	+	% of symbols, rxGrid.
68	+
69	+	% TODO
70	+
71	+	end
72	+
73	+	end
74	+	end
75	+
76	+

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unit04_coding/lab_partial/NRUERxFD.m

1	+	classdef NRUERxFD < matlab.System
2	+	% 5G NR UR receiver class implemented in frequency domain
3	+	properties
4	+	% Configuration
5	+	carrierConfig; % Carrier configuration
6	+	pdschConfig; % Default PDSCH config
7	+	waveformConfig; % Waveform config
8	+
9	+	% OFDM grid
10	+	rxGrid;
11	+
12	+	% Transport block data for last transmission
13	+	targetCodeRate = 490/1024; % Target code rate
14	+	trBlkSizes; % Transport block size
15	+
16	+	% Received data in last slots
17	+	pdschEq; % Equalized PDSCH symbols
18	+	rxBits; % RX bits
19	+
20	+	% DLSCH decoder
21	+	decDLSCH;
22	+
23	+
24	+	end
25	+	methods
26	+	function obj = NRUERxFD(carrierConfig, pdschConfig, ...
27	+	varargin)
28	+	% Constructor
29	+
30	+	% Save the carrier and PDSCH configuration
31	+	obj.carrierConfig = carrierConfig;
32	+	obj.pdschConfig = pdschConfig;
33	+
34	+	% Create the waveform configuration from the carrier
35	+	% configuration
36	+	obj.waveformConfig = nrOFDMInfo(obj.carrierConfig);
37	+
38	+	% Set parameters from constructor arguments
39	+	if nargin >= 1
40	+	obj.set(varargin{:});
41	+	end
42	+
43	+	% Create DLSCH decoder
44	+	obj.decDLSCH = nrDLSCHDecoder('MultipleHARQProcesses', false, ...
45	+	'TargetCodeRate', obj.targetCodeRate, ...
46	+	'LDPCDecodingAlgorithm', 'Layered belief propagation');
47	+
48	+	end
49	+	end
50	+	methods (Access = protected)
51	+
52	+
53	+	function stepImpl(obj, rxGrid, chanGrid, noiseVar)
54	+	% Demodulates and decodes one slot of data
55	+
56	+	% Get PDSCH received symbols and channel estimates
57	+	% from received grid
58	+	[pdschInd,pdschInfo] = nrPDSCHIndices(...
59	+	obj.carrierConfig, obj.pdschConfig);
60	+	[pdschRx, pdschHest] = nrExtractResources(pdschInd, rxGrid,...
61	+	chanGrid);
62	+
63	+	% TODO: Perform the MMSE equalization using the
64	+	% nrEqualizeMMSE() function.
65	+	% Use the PDSCH Rx symbols, PDSCH channel estimate and noise
66	+	% variance as the input. Store the equalized symbols in
67	+	% obj.pdschEq and channel state information in a structure,
68	+	% csi.
69	+	% [obj.pdschEq,csi] = nrEqualizeMMSE(...);
70	+
71	+
72	+	% TODO: Get the LLRs with the nrPDSCHDecode() function.
73	+	% Use carrier and PDSCH configuration, the equalized symbols,
74	+	% and the noise variance, noiseVar.
75	+	% [obj.pdschEq,csi] = nrEqualizeMMSE(...);
76	+
77	+	% Scale LLRs by EbN0.
78	+	% The csi value computed in the nrEqualizeMMSE()
79	+	% function is csi = \|pdschHest\|^2 + noiseVar.
80	+	% Also, the Eb/N0 = snrEq/Qm where Qm is the number of bits
81	+	% per symbol and snrEq is the SNR after equalization,
82	+	%
83	+	% snrEq = (\|pdschHest\|^2 + noiseVar)/noiseVar = csi/noiseVar
84	+	%
85	+	% Hence, Eb/N0 = csi/(noiseVar*Qm).
86	+	% Since the LLRs from the nrPDSCHDecode function are
87	+	% already scaled by 1/noiseVar, we multiply them by csi/Qm.
88	+	csi = nrLayerDemap(csi); % CSI layer demapping
89	+	numCW = length(csi);
90	+	for cwIdx = 1:numCW
91	+	Qm = length(dlschLLRs{cwIdx})/length(rxSym{cwIdx}); % bits per symbol
92	+	csi{cwIdx} = repmat(csi{cwIdx}.',Qm,1); % expand by each bit per symbol
93	+	dlschLLRs{cwIdx} = dlschLLRs{cwIdx} .* csi{cwIdx}(:); % scale
94	+	end
95	+
96	+	% Compute the extra overhead from the PT-RS
97	+	Xoh_PDSCH = 6*obj.pdschConfig.EnablePTRS;
98	+
99	+	% Calculate the transport block size based on the PDSCH
100	+	% allocation and target code rate
101	+	obj.trBlkSizes = nrTBS(obj.pdschConfig.Modulation,obj.pdschConfig.NumLayers,...
102	+	numel(obj.pdschConfig.PRBSet),pdschInfo.NREPerPRB,...
103	+	obj.targetCodeRate,Xoh_PDSCH);
104	+	obj.decDLSCH.TransportBlockLength = obj.trBlkSizes;
105	+
106	+	% Reset the soft buffer
107	+	harqId = 0;
108	+	obj.decDLSCH.resetSoftBuffer(harqId);
109	+
110	+	% TODO: Decode the bits with the obj.decDLSCH() method.
111	+	% Use the scaled LLRs from above. Use a redundancy version,
112	+	% rv = 0, since we are not using HARQ in this lab.
113	+	% rv = 0;
114	+	% obj.rxBit = obj.decDLSCH(...);
115	+
116	+	end
117	+
118	+	end
119	+	end
120	+
121	+

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unit04_coding/lab_partial/NRgNBTxFD.m

1	+	classdef NRgNBTxFD < matlab.System
2	+	% 5G NR gNB transmitter class implemented in frequency domain
3	+	properties
4	+	% Configuration
5	+	carrierConfig; % Carrier configuration
6	+	pdschConfig; % PDSCH configuration
7	+
8	+	% Transport block data for last transmission
9	+	targetCodeRate = 490/1024; % Target code rate
10	+	trBlkSizes; % Transport block size
11	+
12	+	% Transmitted data in last slots
13	+	txBits; % TX bits
14	+
15	+	% DLSCH encoder
16	+	encDLSCH;
17	+
18	+
19	+	end
20	+	methods
21	+	function obj = NRgNBTxFD(carrierConfig, pdschConfig, ...
22	+	varargin)
23	+	% Constructor
24	+
25	+	% Save the carrier and PDSCH configuration
26	+	obj.carrierConfig = carrierConfig;
27	+	obj.pdschConfig = pdschConfig;
28	+
29	+	% Set parameters from constructor arguments
30	+	if nargin >= 1
31	+	obj.set(varargin{:});
32	+	end
33	+
34	+	% Create DLSCH encoder system object
35	+	obj.encDLSCH = nrDLSCH('MultipleHARQProcesses', false, ...
36	+	'TargetCodeRate', obj.targetCodeRate);
37	+
38	+	end
39	+	end
40	+	methods (Access = protected)
41	+
42	+	function txGrid = stepImpl(obj)
43	+	% step implementation. Creates one slot of samples for each
44	+	% component carrier
45	+
46	+
47	+	% Create the OFDM grid representing the array of modulation
48	+	% symbols to be transmitted
49	+	txGrid = nrResourceGrid(obj.carrierConfig, ...
50	+	obj.pdschConfig.NumLayers);
51	+
52	+
53	+	% Get indices on where the PDSCH is allocated
54	+	[pdschInd,pdschInfo] = nrPDSCHIndices(obj.carrierConfig, obj.pdschConfig);
55	+
56	+	% Compute the extra overhead from the PT-RS
57	+	Xoh_PDSCH = 6*obj.pdschConfig.EnablePTRS;
58	+
59	+	% Calculate the transport block size based on the PDSCH
60	+	% allocation and target code rate
61	+	obj.trBlkSizes = nrTBS(obj.pdschConfig.Modulation,obj.pdschConfig.NumLayers,...
62	+	numel(obj.pdschConfig.PRBSet),pdschInfo.NREPerPRB,...
63	+	obj.targetCodeRate,Xoh_PDSCH);
64	+
65	+	% Generate random bits for each codeword and set the transport
66	+	% block
67	+	obj.txBits = cell(obj.pdschConfig.NumCodewords, 1);
68	+	for icw = 1:obj.pdschConfig.NumCodewords
69	+
70	+	% Create random bits
71	+	obj.txBits{icw} = randi([0 1], obj.trBlkSizes(icw), 1);
72	+
73	+	% Encode data
74	+	obj.encDLSCH.setTransportBlock(obj.txBits{icw},icw-1);
75	+	end
76	+
77	+	% Encode the DL-SCH transport blocks. We use a redundancy
78	+	% version (rv) = 0 since we are not simulating HARQ now.
79	+	rv = 0;
80	+	codedTrBlock = obj.encDLSCH(obj.pdschConfig.Modulation, ...
81	+	obj.pdschConfig.NumLayers, pdschInfo.G, rv);
82	+
83	+	% Modulate the PDSCH modulation
84	+	pdschSymbols = nrPDSCH(obj.carrierConfig, obj.pdschConfig, ...
85	+	codedTrBlock);
86	+
87	+	% Map the modulated symbols to the OFDM grid
88	+	txGrid(pdschInd) = pdschSymbols;
89	+
90	+	end
91	+
92	+	end
93	+	end
94	+
95	+

unit04_coding/lab_partial/labPdsch.mlx

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unit04_coding/lab_partial/labPdsch.pdf

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Added lab for unit 4