Turbo coded hybrid ARQ (HARQ) is known as one of the promising error control techniques for high speed wireless packet access. However, in a severe frequency-selective fading channel, the HARQ throughput performance significantly degrades for direct sequence code division multiple access (DS-CDMA) system using rake combining. This problem can be overcome by replacing the rake combining by the f...

Mapping rearrangement (MaRe) for the hybrid ARQ (HARQ) based on the parallel concatenated trellis coded modulation (PCTCM) is analyzed. We demonstrate that the performance of the PCTCM receiver is intrinsically limited by the MaRe design and we propose a new mapping scheme to fit the structure of PCTCM transceivers. Depending on the HARQ scenarios, the proposed scheme offers gains between 0.1 a...

RETRANSMISSION STRATEGIES FOR MOVING NETWORKS OVER RICEAN FADING CHANNELS by Alex Ruiz Lee The problem of designing retransmission protocols based on Hybrid Automatic Repeat reQuest (HARQ) for moving networks over Ricean fading channels has been considered. The scenario of interest consists of one receiver traveling at a given speed while connected to a wireless network based on OFDM (e.g., WiM...

In this paper, we do a performance analysis of the cooperative HARQ protocol in a wireless adhoc multihop network employing spatial ALOHA. We model the nodes in such a network by a homogeneous 2-D Poisson point process. We study the tradeoff between the transport capacity submetrics inherent in the network by optimizing the transport capacity w.r.t the network design parameters, HARQ coding rat...

This paper investigates the performance of hybrid automatic repeat request (HARQ) protocol, considering bubble blockage and Generalized Gamma fading channel in underwater optical wireless communication (UOWC) systems. The system terms bit-error rate throughput is analytically analyzed. Computer simulations using Monte Carlo method are also presented to validate correctness our analysis. From ob...

Reliability-based hybrid ARQ (RB-HARQ) is a recently introduced approach to incremental-redundancy ARQ. In RB-HARQ, the bits that are to be retransmitted are adaptively selected at the receiver based on the estimated bit reliabilities. This technique has the potential to improve performance and minimize retransmission size by targetting those bits that are likely to be in error. However, previo...

Hybrid automatic repeat request (Hybrid ARQ or HARQ), an extension of ARQ that incorporates forward error correction coding (FEC), is a retransmission scheme with errorcontrol method employed in current communications systems. In standard ARQ, redundant bits are added to data to be transmitted using an error-detecting code, e.g., cyclic redundancy check (CRC). The contribution of HARQ is its ef...

In this work, we propose novel HARQ prediction schemes for Cloud RANs (C-RANs) that use feedback over a rate-limited channel (2 - 6 bits) from the Remote Radio Heads (RRHs) to predict at User Equipment (UE) decoding outcome BaseBand Unit (BBU) ahead of actual decoding. particular, Dual Autoencoding 2-Stage Gaussian Mixture Model (DA2SGMM) is trained in an end-to-end fashion whole C-RAN setup. U...

We analyze the optimum threshold value used in determining the modulation and coding scheme (MCS) level of retransmission packets in HARQ schemes. In HARQ schemes, although the first packet is erroneous, it has a considerable energy that can enhance the system performance such as packet error rate (PER) and throughput. Using the existing energy of the first transmission packet, we can save the ...

In this paper, we propose a system suitable for efficient packet data transmission using the Internet Protocol (IP) in wireless 4G systems. It consists of a hybrid type-II Automatic Repeat reQuest (ARQ) scheme combined with an Adaptive Modulation System (AMS) and a time slot scheduler supplied by channel predictions. It is referred to as predictive HARQ-II/AMS. The performance of the system in ...