A Simple Multiuser and Single-User Dual-Mode Downlink System with Limited Feedback

Limited feedback systems that simultaneously transmit to multiple users are noise power limited at low SNR and interference power limited at high SNR. Specifically, there is a sum rate upper bound such that increasing the transmit power alone cannot surpass. In this paper, we propose a dual-mode system that selects between single user mode and multiuser mode. The mobile determines its preferred transmission mode by a simple threshold rule of its SINR. Judiciously combining mobiles' feedback, the base station with MT transmit antennas chooses the better communication mode. It is shown that this proposed system asymptotically achieves unbounded capacity growth when increasing the number of mobiles or when increasing the SNR, without requiring extra feedback bits. We show the asymptotically preferable mode as the number of users and/or SNR increases. Lastly, we use computer simulations to verify our findings.

[1]  Andrea J. Goldsmith,et al.  Sum-rate optimal multi-antenna downlink beamforming strategy based on clique search , 2005, GLOBECOM '05. IEEE Global Telecommunications Conference, 2005..

[2]  Daeyoung Park,et al.  On Scheduling for Multiple-Antenna Wireless Networks Using Contention-Based Feedback , 2007, IEEE Transactions on Communications.

[3]  Nihar Jindal,et al.  Multi-Antenna Broadcast Channels with Limited Feedback and User Selection , 2006 .

[4]  Shlomo Shamai,et al.  The Capacity Region of the Gaussian Multiple-Input Multiple-Output Broadcast Channel , 2006, IEEE Transactions on Information Theory.

[5]  D. Gesbert,et al.  Exploiting multiuser diversity using multiple feedback thresholds , 2005, 2005 IEEE 61st Vehicular Technology Conference.

[6]  Rick S. Blum,et al.  Multiuser diversity for a dirty paper approach , 2003, IEEE Communications Letters.

[7]  Max H. M. Costa,et al.  Writing on dirty paper , 1983, IEEE Trans. Inf. Theory.

[8]  Mohamed-Slim Alouini,et al.  How much feedback is multi-user diversity really worth? , 2004, 2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577).

[9]  A. Lee Swindlehurst,et al.  A vector-perturbation technique for near-capacity multiantenna multiuser communication-part II: perturbation , 2005, IEEE Transactions on Communications.

[10]  Aria Nosratinia,et al.  Exploiting multiuser diversity with only 1-bit feedback , 2005, IEEE Wireless Communications and Networking Conference, 2005.

[11]  Babak Hassibi,et al.  On the capacity of MIMO broadcast channels with partial side information , 2005, IEEE Transactions on Information Theory.

[12]  David Tse,et al.  Opportunistic beamforming using dumb antennas , 2002, IEEE Trans. Inf. Theory.

[13]  A. Nosratinia,et al.  Opportunistic Beamforming with Limited Feedback , 2005, Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005..

[14]  N.D. Sidiropoulos,et al.  On downlink beamforming with greedy user selection: performance analysis and a simple new algorithm , 2005, IEEE Transactions on Signal Processing.

[15]  Robert W. Heath,et al.  Opportunistic feedback for downlink multiuser diversity , 2005, IEEE Communications Letters.

[16]  Wei Yu,et al.  Sum capacity of Gaussian vector broadcast channels , 2004, IEEE Transactions on Information Theory.

[17]  David Tse,et al.  Sum capacity of the vector Gaussian broadcast channel and uplink-downlink duality , 2003, IEEE Trans. Inf. Theory.

[18]  Michael D. Zoltowski,et al.  Multiple Antenna Broadcast Channels With Shape Feedback and Limited Feedback , 2007, IEEE Transactions on Signal Processing.

[19]  David Gesbert,et al.  Memory-based opportunistic multi-user beamforming , 2005, Proceedings. International Symposium on Information Theory, 2005. ISIT 2005..

[20]  Andrea J. Goldsmith,et al.  On the optimality of multiantenna broadcast scheduling using zero-forcing beamforming , 2006, IEEE Journal on Selected Areas in Communications.

[21]  A. Lee Swindlehurst,et al.  A vector-perturbation technique for near-capacity multiantenna multiuser communication-part I: channel inversion and regularization , 2005, IEEE Transactions on Communications.

[22]  Andrea J. Goldsmith,et al.  Duality, achievable rates, and sum-rate capacity of Gaussian MIMO broadcast channels , 2003, IEEE Trans. Inf. Theory.

[23]  Shlomo Shamai,et al.  On the achievable throughput of a multiantenna Gaussian broadcast channel , 2003, IEEE Transactions on Information Theory.

[24]  Nihar Jindal.  MIMO broadcast channels with finite rate feedback , 2005, GLOBECOM.

[25]  Martin Haardt,et al.  Zero-forcing methods for downlink spatial multiplexing in multiuser MIMO channels , 2004, IEEE Transactions on Signal Processing.