DocumentCode :
1418690
Title :
Space-time network coding
Author :
Lai, Hung-Quoc ; Liu, K. J Ray
Author_Institution :
RDER-STA-DS, U.S. Army RDECOM CERDEC, Aberdeen Proving Ground, MD, USA
Volume :
59
Issue :
4
fYear :
2011
fDate :
4/1/2011 12:00:00 AM
Firstpage :
1706
Lastpage :
1718
Abstract :
Traditional cooperative communications can improve communication reliability. However, transmissions from multiple relay nodes are challenging in practice. Single transmissions in time-division multiple-access (TDMA) manner cause large transmission delay, but simultaneous transmissions from two or more nodes using frequency-division multiple access (FDMA) and code-division multiple access (CDMA) are associated with the issue of imperfect frequency and timing synchronization. In this work, a novel framework for cooperative communications is proposed to achieve full spatial diversity with low transmission delay and eliminate the issue of imperfect synchronization. This is realized by the use of space-time network codes (STNCs) associated with a novel concept of wireless network cocast. For a network of N client nodes, R relay nodes and a base node, the STNCs provide a diversity order of (R+1) for each symbol with (N+R) time slots, a reduction from 2N time slots in traditional FDMA and CDMA cooperative communications for N being usually greater than R and from N(R+1) time slots in traditional TDMA cooperative communications. The STNCs are also applied in networks, where the client nodes located in a cluster act as relays to help one another to improve their transmission performance. The performance in clustering setting is studied to show the improvement in power saving, range extension, and transmission rate.
Keywords :
code division multiple access; cooperative communication; diversity reception; network coding; pattern clustering; space-time codes; time division multiple access; CDMA; TDMA; base node; client nodes; clustering setting; code-division multiple access; communication reliability; cooperative communications; multiple relay nodes; power saving; range extension; relay nodes; space-time network coding; spatial diversity; time-division multiple-access; transmission rate; wireless network cocast; Frequency synchronization; MIMO; Multiaccess communication; Protocols; Relays; Synchronization; Cooperative communications; frequency synchronization; linear network coding; space–time network codes; timing synchronization; wireless network cocast;
fLanguage :
English
Journal_Title :
Signal Processing, IEEE Transactions on
Publisher :
ieee
ISSN :
1053-587X
Type :
jour
DOI :
10.1109/TSP.2010.2103063
Filename :
5680658
Link To Document :
بازگشت