Reducing Feedback Requirements of the Multiple Weight Opportunistic Beamforming Scheme via Selective Multiuser Diversity

Nicolaou, M; Doufexi, Angela; Armour, Simon

doi:10.1109/vetecf.2008.333

Cited by 8 publications

(9 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For simplicity, 1 th Q and 2 th Q are of the same value. Using numerical searching we obtain the threshold values under N T =8 and N k =2 in Table I, analogous to [12]. Given target capacity or outage probability and the statistical characteristic of ζ i , the threshold could also be determined.…”

Section: ) Determination Of Thresholdmentioning

confidence: 99%

“…Assume each right singular vector v k,i (t) is quantized into M bits. The feedback load of L eligible users, of which l 1 users select BF at slot t is given by (12). Here CQI feedback load is not considered.…”

Section: Feedback Load Analysismentioning

confidence: 99%

“…Other works focus on opportunistic beamforming (OB) [8][9][10][11][12], i.e. at each time slot only one user among multiple candidates is selected.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, when OB is under discussion CCI is no longer considered. Among the works dealing with OB [8,9] investigate the strategy to achieve multiuser diversity with low feedback cost, [10,11] discuss the way to induce large and fast channel fluctuations and [12] takes both issues into account. In these works each MS is equipped with only one receive antenna, i.e.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Opportunistic transmission in MU-MIMO downlink with reduced feedback and mode adaptation

Yang

et al. 2009

2009 1st International Conference on Wireless Communication, Vehicular Technology, Information Theory and Aerospace &Amp; Elect

View full text Add to dashboard Cite

In this paper we introduced an opportunistic transmission scheme in MU-MIMO downlink with reduced feedback and mode adaptation. In this strategy both base station (BS) and mobile station (MS) are equipped with multiple antennas. Threshold scheme is employed. Only eligible MS whose channel quality exceeds a preset threshold would select transmission mode, including beamforming (BF) and spatial multiplexing (SM) and adaptively feed back channel information. With feedback information, BS schedules one user out of candidate MSs at each time slot. In evaluating the scheme, statistical analysis is employed in company with Monte-Carlo simulation. Results show that with appropriate thresholds and mode adaptation, the proposed scheme can achieve high capacity as well as low feedback load and outage probability.

show abstract

Section: ) Determination Of Thresholdmentioning

confidence: 99%

Section: Feedback Load Analysismentioning

confidence: 99%

“…Other works focus on opportunistic beamforming (OB) [8][9][10][11][12], i.e. at each time slot only one user among multiple candidates is selected.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Opportunistic transmission in MU-MIMO downlink with reduced feedback and mode adaptation

Yang

et al. 2009

2009 1st International Conference on Wireless Communication, Vehicular Technology, Information Theory and Aerospace &Amp; Elect

View full text Add to dashboard Cite

show abstract

“…Therefore the combined use of OFDMA and multiple precoding design results in an excessive feedback overhead. For this reason various approaches for uplink feedback reduction in OFDMA and multiple precoding selection have been developed [12,13]. This section outlines the basic procedure followed for the unitary beamforming, illustrated in Figure 1, based on a pre-defined codebook with partial feedback design, as proposed in [3].…”

Section: Introduction To Beam Selection Withmentioning

confidence: 99%

Performance Analysis for Partial Feedback Downlink MIMO with Unitary Codebook Beamforming for LTE

Nicolaou

Doufexi

Armour

et al. 2009

2009 IEEE International Conference on Communications Workshops

View full text Add to dashboard Cite

Until recently, mobile communication tasks have been grouped into different layers in a hierarchical layer approach. In this conventional approach, layer-specific protocols are developed and optimised independently. As new wireless applications emerge, requiring high data rates and flexibility for supporting applications with significantly varying QoS requirements, it has become imperative that a higher level of communication between adjacent layers needs to be established. A unitary codebook based beamforming approach has been proposed for LTE that incorporates an improved cross-layer interface in order to improve service to users according to specified QoS criteria. This paper examines this beamforming approach under partial feedback conditions for different MIMO configurations. It is shown that non-obvious precoding matrix selection strategies and scheduling policies for the DLC, can achieve superior performance for LTE system, whilst meeting the QoS requirements of urgent users. I.INDRODUCTIONEmerging wireless communications systems that include a variety of different applications (e.g. real time video, voice, data) have changed the scope and design principles of wireless technologies. The need to provide high data rates for users within a congested channel environment has resulted in the emergence of Multiple Input Multiple Output (MIMO) antenna technologies and Orthogonal Frequency Division Multiplexing (OFDM). OFDM splits a high data rate stream into several lower rate orthogonal parallel streams. This approach is an attractive solution towards designing systems that are expected to operate in Non Line-of-Sight (NLOS) channels due to high tolerance to delay spread effects achieved by the a longer symbol duration and the use of a Cyclic Prefix (CP). The additional degree of freedom enabled by the use of multiple antennas at the transmitter and the receiver enables multiple users to be simultaneously scheduled on the same subchannel, or the assignment of multiple streams to the same user.The advent of new wireless applications, has highlighted the need for a better cross-layer cooperation that can support traffic with flexible Quality of Service (QoS) requirements, such as maximum packet delay, constraints of successful packet transmission. Recently, a Multiuser, Multiple Input Multiple Output (MIMO) scheduling and precoding method has been proposed for the Long Term Evolution (LTE) of 3G systems [1], that incorporates an improved interface between the Physical (PHY) and the Data Link Control (DLC) layers in order to provide increased support for on demand QoS [2]. In [3], a precoding method for a MIMO-OFDMA scheme has been proposed in accordance to the LTE standard [1]. This precoding method relies on the use of a known codebook of unitary matrices, which is determined offline, generated according to a Fourier basis that provides uniform coverage across a sector.The benefits from the symbiotic effect of a cross-layer design have been studied in [2]. This paper considers different codebook sizes o...

show abstract

Double-threshold opportunistic transmission strategy for MU-MIMO downlink

Yang

Yao

2009

2009 9th International Symposium on Communications and Information Technology

View full text Add to dashboard Cite

Reducing Feedback Requirements of the Multiple Weight Opportunistic Beamforming Scheme via Selective Multiuser Diversity

Cited by 8 publications

References 11 publications

Opportunistic transmission in MU-MIMO downlink with reduced feedback and mode adaptation

Opportunistic transmission in MU-MIMO downlink with reduced feedback and mode adaptation

Performance Analysis for Partial Feedback Downlink MIMO with Unitary Codebook Beamforming for LTE

Double-threshold opportunistic transmission strategy for MU-MIMO downlink

Contact Info

Product

Resources

About