Opportunistic error correction for MIMO

In this paper, we propose an energy-efficient scheme to reduce the power consumption of ADCs in MIMO-OFDM systems. The proposed opportunistic error correction scheme is based on resolution adaptive ADCs and fountain codes. The key idea is to transmit a fountain-encoded packet over one single sub-carrier per antenna and to transmit more packets than needed for decoding. Comparing to the IEEE 802.11n standard, this approach allows around 83% of power saving in ADCs for a 2 × 2 system and 90% for a 4 × 4 system. With the current FEC scheme defined in the IEEE 802.11n standard, a 4 × 4 system requires twice amount of power in ADCs as a 2 × 2 system when receiving the same amount of information with the same power. However, using opportunistic error correction in a 4 × 4 system costs only around 1.4 times amount of energy in ADCs comparing to a 2 × 2 system.