Capacity of SIMO and MISO Phase-Noise Channels with Common/Separate Oscillators
Journal article, 2015

In multiple antenna systems, phase noise due to instabilities of the radio-frequency (RF) oscillators, acts differently depending on whether the RF circuitries connected to each antenna are driven by separate (independent) local oscillators (SLO) or by a common local oscillator (CLO). In this paper, we investigate the high-SNR capacity of single-input multiple-output (SIMO) and multiple-output single-input (MISO) phase-noise channels for both the CLO and the SLO configurations. Our results show that the first-order term in the high-SNR capacity expansion is the same for all scenarios (SIMO/MISO and SLO/CLO), and equal to 0.5ln(SNR), where SNR stands for the signal-to-noise ratio. On the contrary, the second-order term, which we refer to as phase-noise number, turns out to be scenario-dependent. For the SIMO case, the SLO configuration provides a diversity gain, resulting in a larger phase-noise number than for the CLO configuration. For the case of Wiener phase noise, a diversity gain of at least 0.5ln(M) can be achieved, where M is the number of receive antennas. For the MISO, the CLO configuration yields a higher phase-noise number than the SLO configuration. This is because with the CLO configuration one can obtain a coherent-combining gain through maximum ratio transmission (a.k.a. conjugate beamforming). This gain is unattainable with the SLO configuration.

channel capacity

Phase noise

multiple antennas

Wiener process.

distributed oscillators


M Reza Khanzadi

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Chalmers, Signals and Systems, Communication, Antennas and Optical Networks

GigaHertz Centre

Giuseppe Durisi

Chalmers, Signals and Systems, Communication, Antennas and Optical Networks

Thomas Eriksson

Chalmers, Signals and Systems, Communication, Antennas and Optical Networks

IEEE Transactions on Communications

0090-6778 (ISSN)

Vol. 63 9 3218-3231 7054485

Areas of Advance

Information and Communication Technology

Subject Categories


Communication Systems

Signal Processing



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