Cooperative multiple access channels: Achievable rates and optimal resource allocation

We investigate the multiple access channels (MAC) where sources can cooperate via half-duplex relaying and refer to it as cooperative MAC channels (CMAC). Assuming perfect channel state information (CSI) at the transmitters and the receivers, we determine the bounds on the achievable rate region of a Gaussian CMAC channel and an inner bound on the outage capacity region of a fading CMAC channel. Based on superposition modulation, a half-duplex cooperative relay scheme with optimal resource allocation is proposed to achieve the bounds of capacity region. Analytical results and simulation results show that the achievable rate region of a Gaussian CMAC channel is larger than that of a Gaussian MAC channel with direct transmission (DT) schemes. But they have the same achievable sum rate. Moreover, the proposed scheme can provide higher outage capacity region than DT schemes in a fading MAC channel due to the fact that sources can share the resources with each other to reduce outages.

[1]  Gregory W. Wornell,et al.  Cooperative diversity in wireless networks: Efficient protocols and outage behavior , 2004, IEEE Transactions on Information Theory.

[2]  Elza Erkip,et al.  User cooperation diversity. Part I. System description , 2003, IEEE Trans. Commun..

[3]  Gerhard Kramer,et al.  Capacity Theorems for the Multiple-Access Relay Channel , 2004 .

[4]  Anders Høst-Madsen,et al.  Capacity bounds and power allocation for wireless relay channels , 2005, IEEE Transactions on Information Theory.

[5]  Peter Willett,et al.  The theoretical bandwidth advantage of CDMA over FDMA in a Gaussian MAC , 1999, IEEE Trans. Inf. Theory.

[6]  Aria Nosratinia,et al.  Cooperative communication in wireless networks , 2004, IEEE Communications Magazine.

[7]  A.J. van Wijngaarden,et al.  On the white Gaussian multiple-access relay channel , 2000, 2000 IEEE International Symposium on Information Theory (Cat. No.00CH37060).

[8]  李幼升,et al.  Ph , 1989 .

[9]  Erik G. Larsson,et al.  Cooperative transmit diversity based on superposition modulation , 2005, IEEE Communications Letters.

[10]  Frans M. J. Willems,et al.  The discrete memoryless multiple access channel with partially cooperating encoders , 1983, IEEE Trans. Inf. Theory.

[11]  David Tse,et al.  Outage Capacity of the Fading Relay Channel in the Low-SNR Regime , 2006, IEEE Transactions on Information Theory.

[12]  Robert G. Gallager,et al.  A perspective on multiaccess channels , 1984, IEEE Trans. Inf. Theory.

[13]  Thomas M. Cover,et al.  Elements of Information Theory , 2005 .

[14]  E. Meulen,et al.  Three-terminal communication channels , 1971, Advances in Applied Probability.

[15]  Yingbin Liang,et al.  Rate Regions for Relay Broadcast Channels , 2006, IEEE Transactions on Information Theory.

[16]  Anders Høst-Madsen,et al.  Capacity bounds for Cooperative diversity , 2006, IEEE Transactions on Information Theory.

[17]  Abbas El Gamal,et al.  Capacity theorems for the relay channel , 1979, IEEE Trans. Inf. Theory.

[18]  Amos Lapidoth,et al.  An improved achievable region for the discrete memoryless two-user multiple-access channel with noiseless feedback , 2005, IEEE Transactions on Information Theory.

[19]  Henry Herng-Jiunn Liao,et al.  Multiple access channels (Ph.D. Thesis abstr.) , 1973, IEEE Trans. Inf. Theory.

[20]  Andrea J. Goldsmith,et al.  On the capacity of the vector MAC with feedback , 2006, IEEE Transactions on Information Theory.

[21]  Andrea J. Goldsmith,et al.  Outage capacities and optimal power allocation for fading multiple-access channels , 2005, IEEE Transactions on Information Theory.

[22]  Frans M. J. Willems,et al.  The discrete memoryless multiple-access channel with cribbing encoders , 1985, IEEE Trans. Inf. Theory.

[23]  Michael Gastpar,et al.  Cooperative strategies and capacity theorems for relay networks , 2005, IEEE Transactions on Information Theory.