The Low Density Parity Check (LDPC) codes are powerful, capacity approaching channel codes and have exceptional error correction capabilities. The high degree of parallelism that they offer enables efficient, high throughput hardware architectures. The ntLDPC_WiFi6 IP Core is based on an implementation of QC-LDPC Quasi-Cyclic LDPC Codes and is fully compliant with IEEE 802.11 n/ac/ax standard. The Quasi-Cyclic LDPC codes are based on block-structured LDPC codes with circular block matrices. The entire parity check matrix can be partitioned into an array of block matrices; each block matrix is either a zero matrix or a right cyclic shift of an identity matrix. The parity check matrix designed in this way can be conveniently represented by a base matrix represented by cyclic shifts. The main advantage of this feature is that they offer high throughput at low implementation complexity. The ntLDPC_WiFi6 decoder IP Core may optionally implement one of two approximations of the log-domain LDPC iterative decoding algorithm (Belief propagation) known as either Layered Normalized Offset Min-Sum Algorithm or Layered Lambda-min Algorithm. Selecting between the two algorithms presents a decoding performance .vs. system resources utilization trade-off. The core is highly reconfigurable and fully compliant to the IEEE 802.11 n/ac/ax Wi-Fi4, Wi-Fi5 and Wi-Fi 6 standards. The ntLDPC_WiFi6 encoder IP implements a 81-bit parallel systematic LDPC encoder. An off-line profiling Matlab script processes the original matrices and produces a set of constants that are associated with the matrix and hardcoded in the RTL encoder.
