Mobile Hybrid Arq Communication System Technology Research

On the mobile communication systems,a forward error correction (FEC) or automatic repeat request(ARQ) scheme may be insufficient to achieve the desired performance due to the time-varying nature of the channel.Therefore,the reliability of data and image transmission is usually improved using hybrid ARQ error control scheme which is combined by ARQ and FEC.Hybrid ARQ technique was first designed in the early of 1960's and gains comprehensive research during the latest four decades.Recently,3GPP has proposed it as one of the most pivotal techniques for the high speed packet transmission.In this paper,research actuality and future progress of Hybrid ARQ are first introduced.Because of the excellent performance of Turbo code,IMT 2000 mobile communication systems have adopted them as their channel coding scheme.Different hybrid ARQ schemes based on Turbo codes are then discussed in detail.We try to improve them based on Turbo decoding principle,diversity and interlace techniques.Moreover,Hybrid ARQ systems of type Ⅱwith Incremental Redundancy that employs rate compatible punctured convolutional (RCPC) codes and rate compatible punctured Turbo (RCPT) codes are analyzed respectively and modified a little for the sake of the simplicity of our schemes.Finally,according to CDMA2000 downlink channel we simulate most hybrid ARQ systems mentioned in the paper and compare their performance under six fading channel models.Some hybrid ARQ schemes are recommended in allusion to the specific environments on the basis of the simulation result.