Title :
A Low Complexity User Grouping Based Multiuser MISO Downlink Precoder
Author :
Mohammed, Saif Khan ; Larsson, Erik G.
Author_Institution :
Dept. Electr. Eng. (ISY), Linkoping Univ., Linkoping, Sweden
Abstract :
We consider low complexity precoding for the Multiple Input Single Output (MISO) Gaussian Broadcast channel with Nt antennas at the base station and Nu single antenna users in the downlink. Theoretical studies have suggested high throughput communication with increasing spatial dimensions i.e., min(Nt,Nu). Nevertheless, most modern communication standards are unable to exploit the spatial dimension fully, since they are restricted to orthogonal communication techniques like TDMA/FDMA (Time/Frequency Division Multiplexed Access) which are known to be sub-optimal. This restriction is mostly due to the prohibitive complexity of optimal/near-optimal precoding schemes. On the other hand low complexity techniques like Zero Forcing (ZF) and MMSE have poor sum rate performance. In this paper, we propose a novel low-complexity user grouping based precoding scheme which schedules all users on the same time-frequency resource (i.e., optimal utilization of resources). The proposed precoder is analytically shown to achieve a sum rate performance significantly better than the ZF precoder at similar complexity. Through simulations, it is also observed to achieve a significant fraction of the sum rate achieved by the optimal schemes.
Keywords :
broadcast channels; frequency division multiple access; least mean squares methods; precoding; time division multiple access; MMSE; base station; frequency division multiplexed access; low complexity user grouping; multiple input single output Gaussian broadcast channel; multiuser MISO downlink precoder; near-optimal precoding; single antenna users; time division multiplexed access; zero forcing precoder; Complexity theory; Encoding; Interference; Optimization; Resource management; Transmitters; Vectors;
Conference_Titel :
Global Telecommunications Conference (GLOBECOM 2011), 2011 IEEE
Conference_Location :
Houston, TX, USA
Print_ISBN :
978-1-4244-9266-4
Electronic_ISBN :
1930-529X
DOI :
10.1109/GLOCOM.2011.6133649