Implemented features from RAN1 91. Still need to test.

Author: robmaunder

PDCCH_decoder.m

@@ -43,6 +43,10 @@
 
 addpath 'components'
 
+if A > 140
+    error('polar_3gpp_matlab:UnsupportedBlockLength','A should be no greater than 140.');
+end
+
 if nargin == 4
     RNTI = ones(1,16);
 end

PDCCH_encoder.m

@@ -41,6 +41,11 @@
 
 A = length(a);
 
+if A > 140
+    error('polar_3gpp_matlab:UnsupportedBlockLength','A should be no greater than 140.');
+end
+
+
 % The CRC polynomial used in 3GPP PBCH and PDCCH channel is
 % D^24 + D^23 + D^21 + D^20 + D^17 + D^15 + D^13 + D^12 + D^8 + D^4 + D^2 + D + 1
 crc_polynomial_pattern = [1 1 0 1 1 0 0 1 0 1 0 1 1 0 0 0 1 0 0 0 1 0 1 1 1];

PUCCH_decoder.m

@@ -1,16 +1,16 @@
 function a_hat = PUCCH_decoder(f_tilde, A, L, min_sum)
 % PUCCH_DECODER Physical Uplink Control Channel (PUCCH) polar decoder from 3GPP New
 % Radio, as specified in Section 6.3.1 of TS 38.212 v1.1.1
-%   a_hat = PUCCH_DECODER(f_tilde, A, L, min_sum) decodes the encoded LLR sequence 
-%   f_tilde, in order to obtain the recovered information bit sequence 
+%   a_hat = PUCCH_DECODER(f_tilde, A, L, min_sum) decodes the encoded LLR sequence
+%   f_tilde, in order to obtain the recovered information bit sequence
 %   a_hat.
 %
-%   f_tilde should be a real row vector comprising E number of Logarithmic
+%   f_tilde should be a real row vector comprising G number of Logarithmic
 %   Likelihood Ratios (LLRS), each having a value obtained as LLR =
 %   ln(P(bit=0)/P(bit=1)).
 %
 %   A should be an integer scalar. It specifies the number of bits in the
-%   information bit sequence, where A should be less than E.
+%   information bit sequence, where A should be less than G.
 %
 %   L should be a scalar integer. It specifies the list size to use during
 %   Successive Cancellation List (SCL) decoding.
@@ -21,31 +21,58 @@
 %   better error correction capability than the min-sum, but it has higher
 %   complexity.
 %
-%   a_hat will be a binary row vector comprising A number of bits, each 
+%   a_hat will be a binary row vector comprising A number of bits, each
 %   having the value 0 or 1.
 %
 %   See also PUCCH_ENCODER
 %
-% Copyright © 2017 Robert G. Maunder. This program is free software: you 
-% can redistribute it and/or modify it under the terms of the GNU General 
-% Public License as published by the Free Software Foundation, either 
-% version 3 of the License, or (at your option) any later version. This 
-% program is distributed in the hope that it will be useful, but WITHOUT 
-% ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 
-% FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 
+% Copyright © 2017 Robert G. Maunder. This program is free software: you
+% can redistribute it and/or modify it under the terms of the GNU General
+% Public License as published by the Free Software Foundation, either
+% version 3 of the License, or (at your option) any later version. This
+% program is distributed in the hope that it will be useful, but WITHOUT
+% ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+% FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 % more details.
 
 addpath 'components'
 
-E = length(f_tilde);
+G = length(f_tilde);
 
-% NEED TO ADD SEGMENTATION
+if A < 12
+    error('polar_3gpp_matlab:UnsupportedBlockLength','A should be no less than 12.');
+elseif A <= 19 % Use PCCA-polar
+    % The CRC polynomial used with PCCA-polar in 3GPP PUCCH channel is
+    % D^6 + D^5 + 1
+    crc_polynomial_pattern = [1 1 0 0 0 0 1];
+    
+    % Use one segment
+    C = 1;
+else % Use CA-polar
+    % The CRC polynomial used with CA-polar in 3GPP PUCCH channel is
+    % D^11 + D^10 + D^9 + D^5 + 1
+    crc_polynomial_pattern = [1 1 1 0 0 0 1 0 0 0 0 1];
+    
+    if A >= 360 && G >= 1088
+        if mod(G,2) ~= 0
+            error('polar_3gpp_matlab:UnsupportedBlockLength','G should be divisible by 2 when code block segmentation is used.');
+        end
+        
+        % Use two segments
+        C = 2;
+        
+    else
+        % Use one segment
+        C = 1;
+    end
+    
+end
 
-% NEED TO CONFIRM CRC
+if G > 8192*C
+    error('polar_3gpp_matlab:UnsupportedBlockLength','G is too long.');
+end
+    
 
-% The CRC polynomial used in 3GPP PUCCH channel is
-% D^11 + D^10 + D^9 + D^5 + 1
-crc_polynomial_pattern = [1 1 1 0 0 0 1 0 0 0 0 1];
 
 % The CRC has P bits. P-min(P2,log2(L)) of these are used for error
 % detection, where L is the list size. Meanwhile, min(P2,log2(L)) of
@@ -56,50 +83,78 @@
 P2 = 3;
 
 % Determine the number of information and CRC bits.
-K = A+P;
-
-if K-3 < 12
-    error('polar_3gpp_matlab:UnsupportedBlockLength','K-3 should be no less than 12.');
-end
+K = ceil(A/C)+P;
 
 % Determine the number of bits used at the input and output of the polar
 % encoder kernal.
-N = get_3GPP_N(K,E,10); % n_max = 10 is used in PUCCH channels
+N = get_3GPP_N(K,G/C,10); % n_max = 10 is used in PUCCH channels
 
 % Get a rate matching pattern.
-[rate_matching_pattern, mode] = get_3GPP_rate_matching_pattern(K,N,E);
+[rate_matching_pattern, mode] = get_3GPP_rate_matching_pattern(K,N,G/C);
 
 % Get a sequence pattern.
 Q_N = get_3GPP_sequence_pattern(N);
 
-% Perform channel deinterleaving
-channel_interleaver_pattern = get_3GPP_channel_interleaver_pattern(E);
-e_tilde = zeros(1,E);
-e_tilde(channel_interleaver_pattern) = f_tilde;
+% Get the channel interleaving pattern
+channel_interleaver_pattern = get_3GPP_channel_interleaver_pattern(G/C);
+
 
-if K - 3 <= 22
-    % Use PC-polar
-    n_PC = 3;
 
+if A <= 19 % Use PCCA-polar
+    
+    % Perform channel interleaving
+    e_tilde = zeros(1,G);
+    e_tilde(channel_interleaver_pattern) = f_tilde;
+    
+    % We use 3 PC bits
+    n_PC = 3;
+    
     % Get an information bit pattern.
     info_bit_pattern = get_3GPP_info_bit_pattern(K+n_PC, Q_N, rate_matching_pattern, mode);
-
+    
     % Get a PC bit pattern.
-    if E-K+3 > 192
+    if G-K+3 > 192
         PC_bit_pattern = get_PC_bit_pattern(info_bit_pattern, Q_N, n_PC, 1);
-    else        
+    else
         PC_bit_pattern = get_PC_bit_pattern(info_bit_pattern, Q_N, n_PC, 0);
     end
 
     % Perform polar decoding.
     a_hat = PCCA_polar_decoder(e_tilde,crc_polynomial_pattern,info_bit_pattern,PC_bit_pattern,5,rate_matching_pattern,mode,L,min_sum,P2);
-else
-    % Use CA-polar
-    
+else % Use CA-polar
+        
     % Get an information bit pattern.
     info_bit_pattern = get_3GPP_info_bit_pattern(K, Q_N, rate_matching_pattern, mode);
-    % Perform polar decoding.
-    a_hat = CA_polar_decoder(e_tilde,crc_polynomial_pattern,info_bit_pattern,rate_matching_pattern,mode,L,min_sum,P2);
-end   
-
-% SEGMENTATION
+        
+    if C == 2
+        a_hat = zeros(1,A);
+        
+        info_bit_pattern2 = info_bit_pattern;
+        if mod(A,2) ~= 0 % If a zero was prepended to the first segment during encoding
+            % Treat the first information bit as a frozen bit
+            info_bit_pattern2(find(info_bit_pattern == 1,1,first)) = 0;
+        end
+        
+        % Perform channel interleaving for first segment.
+        e_tilde = zeros(1,G/C);        
+        e_tilde(channel_interleaver_pattern) = f_tilde(1:G/C);
+        
+        % Perform polar decoding for first segment.
+        a_hat(1:floor(A/C)) = CA_polar_decoder(e_tilde,crc_polynomial_pattern,info_bit_pattern2,rate_matching_pattern,mode,L,min_sum,P2);
+        
+        % Perform channel interleaving for second segment.
+        e_tilde(channel_interleaver_pattern) = f_tilde(G/C+1:G);
+        
+        % Perform polar decoding for second segment.
+        a_hat(floor(A/C)+1:A) = CA_polar_decoder(e_tilde,crc_polynomial_pattern,info_bit_pattern,rate_matching_pattern,mode,L,min_sum,P2);
+    else
+        % Perform channel interleaving
+        e_tilde = zeros(1,G);        
+        e_tilde(channel_interleaver_pattern) = f_tilde;
+        
+        % Perform polar decoding.
+        a_hat = CA_polar_decoder(e_tilde,crc_polynomial_pattern,info_bit_pattern,rate_matching_pattern,mode,L,min_sum,P2);
+        
+    end
+end
+end