The New Jersey Institute of Technology's
Electronic Theses & Dissertations Project

Title:	New hybrid automatic repeat request (HARQ) combining with space time block coding (STBC) in invariant and variant fading channel
Author:	Malagarriga Vilella, Guillem Ernest
View Online:	njit-etd2006-010 (xiii, 99 pages ~ 7.1 MB pdf)
Department:	Department of Electrical and Computer Engineering
Degree:	Master of Science
Program:	Telecommunications
Document Type:	Thesis
Advisory Committee:	Bar-Ness, Yeheskel (Committee chair) Haimovich, Alexander (Committee member) Abdi, Ali (Committee member)
Date:	2006-01
Keywords:	Transmission order Channel matrix
Availability:	Unrestricted
Abstract:	Hybrid Automatic Repeat reQuest (HARQ) combining for space time block coding Multiple Input Multiple Output (MIMO) system consisting of N transmit antennas and M receive antennas (NxM) in a time invariant channel and in a time varying channel is proposed and its performance is analyzed. Based on the measured channel matrix, the receiver chooses the best retransmission order and communicated it to the transmitter. The scheme, where this algorithm is performed, is a combination of a precombining HARQ scheme and the Multiple Alamouti Space-Time Block Coding (MASTBC), which is suitable for more than 2 transmit antennas. The combination of this two techniques increase the efficiency of the HARQ packet transmission by exploiting both the spatial and time diversity of the MIMO channel. With MA-STBC, there exist different signal packets alternatives for retransmission that can better exploit the characteristics of the channel. An algorithm that chooses the best signal sequence alternatives for retransmission and which exploit better the characteristics of the current channel is proposed. Simulations results show that using the proposed selection algorithm results in a better performance than with random selection. These simulations are performed in invariant and variant channel, and performances are compared with other HARQ schemes.