WIP Channel Estimation

CMakeLists.txt

@@ -24,7 +24,11 @@ add_executable(tetra
         src/utils/bit_vector.cpp
         src/utils/viter_bi_codec.cpp)
 
+add_executable(tetra-puncturing
+               src/examples/tetra_puncturing.cpp)
+
 target_compile_options(tetra PUBLIC -std=c++17 -Wall -Wno-unused-variable)
+target_compile_options(tetra-puncturing PUBLIC -std=c++17 -Wall -Wno-unused-variable)
 
 include_directories(src)
 
@@ -38,3 +42,4 @@ include_directories(${CMAKE_SOURCE_DIR}/include)
 target_link_libraries(tetra ZLIB::ZLIB fmt::fmt nlohmann_json::nlohmann_json)
 
 install(TARGETS tetra DESTINATION bin)
+install(TARGETS tetra-puncturing DESTINATION bin)

src/examples/tetra_puncturing.cpp

@@ -0,0 +1,51 @@
+#include <functional>
+#include <iostream>
+#include <vector>
+
+auto puncture(std::size_t num_bits, std::vector<int> P, std::function<int(int)> i_from_j) -> std::vector<int> {
+    auto t = P.size() - 1;
+
+    auto period = 8;
+
+    std::vector<int> res(num_bits * 4, 0);
+
+    for (auto j = 1; j <= res.size(); j++) {
+        auto i = i_from_j(j);
+        auto k = period * ((i - 1) / t) + P[i - t * ((i - 1) / t)];
+        if (k - 1 < res.size())
+            res[k - 1] = j;
+    }
+
+    return res;
+}
+
+auto print(std::vector<int> const& res) -> void {
+    for (auto i = 0; i < res.size();) {
+        auto j = i;
+        std::cout << "  ";
+        for (; j < i + 16; j++) {
+            std::cout << res[j] << " ";
+        }
+        std::cout << std::endl;
+        i = j;
+    }
+}
+
+auto main(int argc, char** argv) -> int {
+    auto rate_2_3 = puncture(4, {0, 1, 2, 5}, [](int j) { return j; });
+    auto rate_1_3 = puncture(4, {0, 1, 2, 3, 5, 6, 7}, [](int j) { return j; });
+    auto rate_292_432 = puncture(11 * 4, {0, 1, 2, 5}, [](int j) { return j + (j - 1) / 65; });
+    auto rate_148_432 = puncture(3 * 4, {0, 1, 2, 3, 5, 6, 7}, [](int j) { return j + (j - 1) / 35; });
+
+    std::cout << "Rate 2/3:" << std::endl;
+    print(rate_2_3);
+
+    std::cout << "Rate 1/3:" << std::endl;
+    print(rate_1_3);
+
+    std::cout << "Rate 292/432:" << std::endl;
+    print(rate_292_432);
+
+    std::cout << "Rate 148/432:" << std::endl;
+    print(rate_148_432);
+}