A Hybrid Automatic Repeat Request (HARQ) with Turbo Codes in OFDM System

In this paper a hybrid automatic repeat request (HARQ) with turbo codes in OFDM system, and the differences hybrid ARQ methods designed for Turbo-coded transmissions on OFDM are presented. Two kinds of modified methods, one without ARQ and the other one are with HARQ: HARQ type-I and HARQ type-II. The latter scheme is based on a combination of the transmitted packets, just before the turbo-decoder , we also compare two modified systems, one does not utilize Forward Error Correction/ARQ (FEC/ARQ) at link layer (referred to as predictive AMS) and the other one has no access to the channel prediction. The simulation results show that our proposed satisfy the Quality of Service (QoS) requirements with advantages to the former in terms of efficient usage of channel capacity.