A MIMO Antenna Structure that Combines Transmit Beamforming and Spatial Multiplexing

Antenna grouping algorithms are hybrids of transmit beamforming and spatial multiplexing. With antenna grouping, we can achieve combining gain through transmit beamforming, and high spectral efficiency through spatial multiplexing. In an independent identically distributed channel, the antenna grouping method has better bit error rate (BER) performance than the beamforming method. However, if the channel is correlated, then the BER performance of antenna grouping degrades. In that case, it is better to use beamforming instead of antenna grouping. In this article, we investigate the mode selection algorithms which select between the antenna grouping and the beamforming modes. By selecting a suitable mode for a given channel, we can achieve more robustness of the system performance. We introduce several mode selection criteria as well as a low complexity criterion which is derived from a low complexity antenna grouping algorithm. Simulation results show that the proposed mode selection algorithm performs better than the antenna grouping and the beamforming modes in various channel conditions.

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“…In this algorithm, the grouping criterion is the sum capacity of sub-channels [8]. The sum capacity of subchannels is…”

Section: Reviews Of Antenna Groupingmentioning

confidence: 99%

“…Antenna grouping is a combination of beamforming and spatial multiplexing [8]. We also introduced some antenna grouping criteria [9].…”

Section: Introductionmentioning

confidence: 99%

Adaptive selection of antenna grouping and beamforming for MIMO systems

Kim

Lee

2011

J Wireless Com Network

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“…The effect of spatial multiplexing of MIMO is considered in [6][7][8][9] and especially the effect of power allocation on resource allocation is considered in [6,7]. Usually MIMO Provides two types of gain to achieve fair power allocation i.e.…”

Section: Introductionmentioning

confidence: 99%

“…one is the spatial multiplexing (SM) gain and other is the diversity gain. The trade-off between these two types of gain has been studied in detail in [8]. In general, the resource allocation of MIMO systems widely varying with number of transmit and or receive antennas, target signal to noise ratio (SNR), transmission schemes, correlation among channel coefficients, etc.…”

Section: Introductionmentioning

confidence: 99%

Efficient Resource Allocation of Service Differentiated Multiuser MIMO Systems Using Power Control

Balaji

Nithyanandan

Mallick

2016

JGE

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This paper considers power allocation across MIMO channels for transmitting two different Classes of Service. MIMO provides multiple parallel channels and it transmits different types of services separately because of different Quality of Service requirements. A high priority class of service named as Constant Bit Rate Traffic has limited delay constraints. So priority is given to this traffic in power allocation and then remaining power is allocated to other services i.e. here Best Effort Traffic based on water-filling algorithm. Analytical expressions are presented to assess the outage probability in terms of average access time and the effect of channel estimation error in throughput is also studied. Numerical results and Analysis are also provided to evaluate the Performance indices like outage probability, throughput and probability of access of both classes of service by optimally allocating the power. The Analysis is carried out for uncorrelated Rayleigh-fading channels with and without interference.

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“…Beamforming combined with spatial multiplexing offers one approach to realize full diversity full rate data transmission [11]. As a practical example, the dual-stream closed loop transmit diversity of the 3GPP Universal Mobile Telecommunications System (UMTS) [12] represents an approach, in which each of the two data streams is transmitted in a digital precoding (beamforming) mode from both of the TX antennas.…”

Section: Introductionmentioning

confidence: 99%

Performance of opportunistic fixed-beam spatial multiplexing in OFDMA uplink

Ylitalo

2014

J Wireless Com Network

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Adaptive spatial multiplexing (SM) Multiple Input Multiple Output (MIMO) techniques enhance the spectral efficiency of wideband wireless communications in favorable radio channel conditions. In this study, we show the benefits of combining a traditional fixed-beam scheme and multiuser opportunistic radio resource allocation in space-time-frequency domains. This combining is feasible in wideband Orthogonal Frequency Domain Multiple Access (OFDMA) systems such as the Universal Mobile Telecommunications System (UMTS) Long Term Evolution (LTE). This study brings novel knowledge which indicates that an orthogonal fixed beam approach benefits from opportunistic radio resource allocation clearly more than a conventional antenna domain approach in frequency-selective radio channels. It was found out that the fixed beam radio link performance is enhanced in wideband adaptive radio links due to the fact that orthogonal beams reduce correlation between the MIMO channels in the allocated sub-bands. Moreover, beamforming gains bring higher Eigenvalues of the MIMO channel matrix in the opportunistically selected sub-bands. It is shown that the fixed beam deployment changes the distribution of the MIMO channel correlation values and Eigenvalues in a manner which enhances opportunistic multiuser gains in wideband time-frequency-selective MIMO radio channels. Simulation results with 2 × 2 spatial multiplexing in an OFDMA uplink indicate that the proposed beam domain scheme gives up to 80% data throughput gain over the corresponding antenna domain scheme in a pedestrian microcell environment.

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A MIMO Antenna Structure that Combines Transmit Beamforming and Spatial Multiplexing

Cited by 28 publications

References 19 publications

Adaptive selection of antenna grouping and beamforming for MIMO systems

Adaptive selection of antenna grouping and beamforming for MIMO systems

Efficient Resource Allocation of Service Differentiated Multiuser MIMO Systems Using Power Control

Performance of opportunistic fixed-beam spatial multiplexing in OFDMA uplink

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