METHOD FOR FASTER AND LOWER POWER CONSUMPTION OF ITERATIVE DECODING ALGORTIHMS WHEN USING A TYPE-II HYBRID ARQ TRANSMISSION SCHEME.
Original Publication Date: 2002-Jul-29
Included in the Prior Art Database: 2002-Jul-29
Today's wireless systems must provide reliable data services. For wired links, reliability is traditionally obtained thanks to repetition. A packet is retransmitted when the previous attempt was unsuccessful. Such mechanism is named ARQ (Automatic Repeat Request). In the case of wireless transmissions, because of the poor quality of the link, packets should be protected against the channel noise. Protection is given by forward error coding (FEC), e.g. transmitting additional bits to the packet. However, to provide the same quality as in wired system, FEC overhead could lead to very inefficient transmissions. As a result, hybrid schemes, combining FEC and ARQ has been defined. In parallel, recent classes of FEC, such as the Turbo-Codes or Low Density Parity check (LDPC) have appeared or reappeared thanks to the iterative decoding technique which provides very good protection for an acceptable complexity. These schemes outperforms all classical coding schemes. Combining iterative decoding and ARQ in an efficient way should lead to very powerful schemes to provide efficient packet transmission over a wireless interface.