Iterative decoding in a two-node distributed array

Abstract

This paper investigates the possibility of using a network-based approach to obtain spatial diversity without the use of physical antenna arrays. To this end, we examine the simple case of a two-node network. A distant transmitter sends a packet of coded data bits to the two nodes in the network. Each of the two nodes receives an independent copy of the transmitted signal. Each node decodes the signal that it receives and generates reliability estimates (soft outputs) for the transmitted data bits. The two nodes then exchange soft outputs of a small portion of the bits that are least reliable. Upon receiving additional information about the least reliable bits from another node, a node will restart the decoding process. This process of information exchange and iterative decoding then continues for a number of iterations. With a properly chosen coding and information exchange strategy, simulation results show that a close-to-full diversity advantage can be achieved using the proposed scheme, requiring exchanging only a small amount of information between the two nodes.