Abstract
Hybrid precoding has been recently proposed as a cost-effective transceiver solution for millimeter wave systems. While the number of radio frequency chains has been effectively reduced in existing works, a large number of high-precision phase shifters are still needed. Practical phase shifters are with coarsely quantized phases, and their number should be reduced to a minimum due to cost and power consideration. In this paper, we propose a novel hardware-efficient implementation for hybrid precoding, called the fixed phase shifter (FPS) implementation. It only requires a small number of phase shifters with quantized and fixed phases. To enhance the spectral efficiency, a switch network is put forward to provide dynamic connections from phase shifters to antennas, which is adaptive to the channel states. An effective alternating minimization algorithm is developed with closed-form solutions in each iteration to determine the hybrid precoder and the states of switches. Moreover, to further reduce the hardware complexity, a group-connected mapping strategy is proposed to reduce the number of switches. Simulation results show that the FPS fully-connected hybrid precoder achieves higher hardware efficiency with much fewer phase shifters than existing proposals. Furthermore, the group-connected mapping achieves a good balance between spectral efficiency and hardware complexity.
Original language | English |
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Pages (from-to) | 282-297 |
Number of pages | 16 |
Journal | IEEE Journal on Selected Topics in Signal Processing |
Volume | 12 |
Issue number | 2 |
DOIs | |
Publication status | Published - May 2018 |
Externally published | Yes |
Keywords
- Alternating minimization
- hardware efficiency
- hybrid precoding
- large-scale antenna arrays
- millimeter wave communications
ASJC Scopus subject areas
- Signal Processing
- Electrical and Electronic Engineering