In this paper, we investigate joint relay and jammer selection in two-way
cooperative networks, consisting of two sources, a number of intermediate
nodes, and one eavesdropper, with the constraints of physical layer security.
Specifically, the proposed algorithms select two or three intermediate nodes to
enhance security against the malicious eavesdropper. The first selected node
operates in the conventional relay mode and assists the sources to deliver
their data to the corresponding destinations using an amplify-and-forward
protocol.
It has been well recognized that channel state information (CSI) feedback is
of great importance for dowlink transmissions of closed-loop wireless networks.
However, the existing work typically researched the CSI feedback problem for
each individual mobile station (MS), and thus, cannot efficiently model the
interactions among self-interested mobile users in the network level.
In this paper, we consider a general bi-directional relay network with two
sources and N relays when neither the source nodes nor the relays know the
channel state information (CSI). A joint relay selection and analog network
coding using differential modulation (RS-ANC-DM) is proposed. In the proposed
scheme, the two sources employ differential modulations and transmit the
differential modulated symbols to all relays at the same time. The signals
received at the relay is a superposition of two transmitted symbols, which we
call the analog network coded symbols.
In this paper, we propose an analog network coding scheme with differential
modulation (ANC-DM) using amplify-and-forward protocol for bidirectional relay
networks when neither the source nodes nor the relay knows the channel state
information (CSI). The performance of the proposed ANC-DM scheme is analyzed
and a simple asymptotic bit error rate (BER) expression is derived. The
analytical results are verified through simulations. It is shown that the BER
performance of the proposed differential scheme is about 3 dB away from that of
the coherent detection scheme.