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This paper considers noncoherent cooperative decode-and-forward(DF) halfduplex multi-branch relay systems.Each relay branch is modeled as a probabilistic transition system at the last hop,and thus it can be considered as a relaying chain comprising multi-hop relays.An approximation to the generalized maximum likelihood(ML) noncoherent block detection is derived for uncoded M-ary modulation in a faded noisy environment.In particular,the derived noncoherent block detection in a noiseless case is equivalent to a multichannel reception with full diversity.Furthermore,the generalized detection is extended specifically to block coded M-ary phase shift keying(MPSK) modulation.For a DF three node relay system using block coded quadrature phase shift keying(QPSK),simulation results are provided to examine the end-to-end error performance of the noncoherent detection with considering the effects of network geometry and power allocation,respectively.It is shown that under a fixed power allocation,a proper relay placement can yield near full diversity for large signal-to-noise ratio.
This paper considers noncoherent cooperative decode-and-forward (DF) halfduplex multi-branch relay systems. Each relay branch is modeled as a probabilistic transition system at the last hop, and thus it can be considered as a relaying chain to multi-hop relays .An approximation to the generalized maximum likelihood (ML) noncoherent block detection is derived for uncoded M-ary modulation in a faded noisy environment. In particular, the derived noncoherent block detection in a noiseless case is equivalent to a multichannel reception with full diversity. The generalized detection is extended to block coded M-ary phase shift keying (MPSK) modulation. For a DF three node relay system using block coded quadrature phase shift keying (QPSK), the simulation results are provided to examine the end-to- -end error performance of the noncoherent detection with considering the effects of network geometry and power allocation, respectively. It shows shown under a fixed power allocation , a proper relay placement can yield near full diversity for large signal-to-noise ratio.