On the throughput of wireless interference networks with limited feedback

Abstract

Abstract-Considering a single-antenna M -user interference channel with symmetrically distributed channel gains, when the channel state information (CSI) is globally available, applying the ergodic interference alignment scheme, each transmitterreceiver pair achieves a rate proportional to 1 ⁄2 of a single user's interference-free achievable rate. This is substantially higher than the achievable rate of the conventional orthogonal transmission schemes such as TDMA. Since the rigid requirement on the CSI may be difficult to realize in practice, in this paper we investigate the performance of applying the ergodic interference alignment scheme when the estimation of each channel gain is made globally known through exploiting only a limited feedback signal from the associated receiver of that channel. Under a block fading environment, we provide a lower bound on the achievable average throughput of the network. Our results imply that the better performance of interference alignment over TDMA may still exist even without the assumption of perfect CSI. Also, the trade off between allocating feedback rate of each receiver to the desired channel or the interference channels at deferent SNR region investigated.

Power control in wireless interference networks with limited feedback

“…Thus, the network is interference-limited and it is preferred to more accurately perform interference alignment rather than power control. This result coincides with the trade-off observed in [6].…”

“…However, the bandwidth of the feedback channels is limited in practice so that the terminals may not be able to attain sufficiently accurate CSI. It has been shown that even with limited feedback, if proper rate adaptation is performed the interference alignment scheme can still outperform TDMA, in terms of sum throughput [6].…”

“…For instance, in a class of systems considered in [6] given that the transmission powers are fixed a maximum sum throughput is always desired. Thus, rate adaptation is performed among the transmitters.…”

Optimal power allocation for pilot-assisted interference alignment in MIMO interference networks: Test-bed results

“…Also, digital/analog channel state feedback schemes have been proposed in the literature to acquire CSI estimation at transmitters (see e.g. [7], [8], [9]). …”

Ergodic interference alignment with noisy channel state information

“…Thus, it provides either the quantized version or the un-coded version of the channel gains to the other terminals through digital feedback signals or analog feedback signals, respectively. It has been shown that if the number of feedback bits of the digital feedback signals [7]- [10] or the transmission powers of the analog feedback signals [11] properly scale with transmission power, the outstanding performance of interference alignment is still achievable. Furthermore, it has been shown in reference [10] that even with a limited number of feedback bits, the throughput of applying interference alignment can still be larger than that achieved by TDMA.…”