IEEE 802.11n/802.11ac (WiFi) LDPC Decoder
The WiFi family of standards (IEEE 802.11) is used for Wireless Local Area Networks (WLANs). Its first version from 1997 has been extended by many amandments such as IEEE 802.11n-2009. This amendment was developed in particular for high throughputs of 600 Mbit/s on the air interface. The standard uses convolutional codes for forward error correction as minimum requirement. LDPC codes are optionial within the standard but because of their superiority over convolutional codes they are widely used today. The LDPC codes defined in IEEE 802.11n-2009 are also used in the current draft of IEEE 802.11ac. This draft intends to increase the data rates of the WiFi standard to up to 6.93 Gbit/s.
Wireless Local Area Networks (WLAN)
Further High-throughput Applications
Standard Features the Core Supports
Compliant with IEEE 802.11n-2009.
Compliant with IEEE P802.11ac (draft).
Support for all LDPC code rates (1/2, 2/3, 3/4, 5/6).
Support for all LDPC block lengths (648, 1296, and 1944 bits).
Gains up to 3 dB compared to Viterbi decoders.
Low-power and low-complexity design.
Layered LDPC decoder architecture, for faster convergence behavior.
Block-to-block on-the-fly configuration.
Early stopping criterion for iterative LDPC decoder, saving a considerable amount of energy.
Configurable amount of LDPC decoding iterations for trading-off throughput and error correction performance.
Collection of statistic information (number of modified information bits, number of iterations, decoding successful).
Available for ASIC and FPGAs (Xilinx, Altera).
Deliverable includes VHDL source code or synthesized netlist, VHDL or SystemC testbench, and Matlab, C or C++ bit-accurate simulation model.
The newest IP core from Creonic is an LDPC decoder for the IEEE 802.11n/ac standards (WiFi or WLAN). The standards require high data rates of up to 600 Mbit/s for 802.11n and up to 7 Gbit/s for 802.11ac. The Creonic LDPC decoder achieves data rates of hundreds of Mbit/s even on low-cost FPGAs. Therefore it ideally suited to satisfy the high demands on forward error correction of the 802.11n and 802.11ac standards.