Proceedings ArticleDOI
CSI Reference Signal Designs for Enabling Closed-Loop MIMO Feedback
Timothy A. Thomas,Bishwarup Mondal,Amitava Ghosh +2 more
- pp 1-5
TLDR
Three possible CSI RS designs for enabling such closed- loop feedback in light of the strong interference environment are described and some tradeoffs between the designs are discussed.Abstract:
Obtaining reliable channel state information (CSI) in future wireless standards is critical for the operation of downlink closed-loop techniques such as SU-MIMO, MU-MIMO, and coordinated multipoint (CoMP). However, this CSI is difficult to obtain especially when considering the potentially strong interference from neighboring sectors/base stations on the downlink reference symbols (RSs, aka pilot symbols) used to obtain the CSI. This paper describes three possible CSI RS designs for enabling such closed- loop feedback in light of the strong interference environment and discusses some tradeoffs between the designs. First, two code-division multiplexing (CDM) designs are proposed where one has nine orthogonal sequences and the other has three orthogonal sequences. Next a new CSI-RS design is described which uses mutually unbiased bases (MUB) to provide a 6 dB quasi-orthogonal gain over neighboring cells. The MUB design is shown in system-level simulation to have performance close to a design with 9 orthogonal sequences while providing a finer frequency-domain sampling than the 9- orthogonal approach.read more
Citations
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Patent
Methods of channel state information feedback and transmission in coordinated multi-point wireless communications system
TL;DR: In this paper, a method of operating an eNB in a wireless communication network is provided, wherein the eNB is configured for coordinated multipoint (CoMP) transmission, and the method comprises determining whether to use a fall back transmission scheme for communicating with a UE in the network.
Patent
Method for initializing sequence of reference signal and base station using the same
TL;DR: In this paper, a method and an apparatus for scrambling sequence initialization for downlink demodulation reference signal (DL DMRS) applied to the multi-user (MU) multi-input multi-output (MU-MIMO) in a coordinated multiple point (CoMP) scenario are provided.
Patent
Method and apparatus for pilot signal processing in a wireless communication system
TL;DR: In this article, a wireless communication system is provided that spreads pilot signals, or channel state information reference signals (CSI-RSs), using a spreading code chosen from a set of mutually unbiased bases (MUBs).
Patent
Antenna allocation apparatus and method for cellular mobile communication system
TL;DR: In this paper, a method and apparatus for selecting and allocating antennas efficiently is provided, which includes transmitting, to a UE, information indicating a configuration of a plurality of Channel Status Information Reference Signals (CSI-RSs) through UE specific signaling during an initial access attempt with the UE; receiving, from the UE, CSI-RS measurement results indicating configured CSI-RSSs; transmitting CSIRSs corresponding to a set of available distributed ports (D-ports) based on received signal strength information included in results of the CSI- RS measurement; and determining a
Journal ArticleDOI
Location-assisted clustering and scheduling for coordinated homogeneous and heterogeneous cellular networks
TL;DR: Efficient location‐assisted limited‐feedback schemes for homogeneous and heterogeneous cellular networks are proposed and a hybrid mode transmission scheme with reduced feedback requirement is proposed for a homogeneous network.
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