On the Two-User MISO Interference Channel With Single-User Decoding: Impact of Imperfect CSIT and Channel Dimension Reduction

C-RAN Zero-Forcing with Imperfect CSI: Analysis and Precode\&Quantize Feedback

“…Thus, Ξ 1 = 0, which establishes the desired result. To complete the proof, we apply Propositions 10,11,12,13 to (42), and in turn, substitute the result in (40), which establishes the desired result.…”

“…Proof of Theorem 1: By the assumptions of Theorem 1 and using ( 9), ( 10), (11) and (12) it follows that…”

“…This assumption is applicable if, for example, S-RRHs are placed on the edges of a regular polygon with M nodes and MSs are placed close to each other at the center of that polygon. 11 Then, MSs have approximately the same long term channel attenuation to each S-RRH. In a rich scattering environment, the MSs will experience independent fading.…”

“…However, while the Xn-link is low latency, it may be rate-limited; a factor that decreases the CSI accuracy at the CU and has an extremely negative effect on the performance of JT, which is highly sensitive to inaccurate CSI. Downlink transmission with perfect and imperfect CSI by a single transmitter [9][10][11] as well as with multiple transmitters employing JT [2,[12][13][14][15][16][17][18] is an important, well-studied topic. Imperfect CSI may result from the limited wireless feedback-channel between MSs to the transmitters [11][12][13][14].…”

“…Downlink transmission with perfect and imperfect CSI by a single transmitter [9][10][11] as well as with multiple transmitters employing JT [2,[12][13][14][15][16][17][18] is an important, well-studied topic. Imperfect CSI may result from the limited wireless feedback-channel between MSs to the transmitters [11][12][13][14]. We focus on a different case where there is channel reciprocity (e.g., time division duplex).…”