Robustness of a time reversal system: From ultra-wide to narrow bandwidths

Naqvi, Ijaz Haider; Aleem, Saad Abdul; Usman, Ovais Bin; Ali, Saqib; Besnier, Philippe; Zein, Ghaïs El

doi:10.1109/wcnc.2012.6214394

Cited by 5 publications

(7 citation statements)

References 20 publications

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“…The time reversal (TR) technique is one of the most popular forms of linear precoding, especially for ultra-wideband (UWB) systems over multipath channels. It is considered as a beamforming technique [2][3][4][5][6][7][8][9][10][11][12][13][14]. TR tightly focuses the energy of all the taps of the propagation channel, in the time and space domains at the intended terminals by utilizing the time-reversed of channel impulse response (CIR) to prefilter transmit signals.…”

Section: Introductionmentioning

confidence: 99%

“…The analysis conducted in [2,5,11] considers specific wideband channels where the average power of each tap decays exponentially. However, the applications of TR techniques can be completely extended to conventional broadband systems as shown in [11][12][13]. In fact, a channel with a narrower bandwidth has a smaller multipath delay spread [14].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Generalized analysis of MU-MISO time reversal-based systems over correlated multipath channels with estimation error

Tran

Nguyen

Hong

2015

AEU - International Journal of Electronics and Communications

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Generalized analysis of MU-MISO time reversal-based systems over correlated multipath channels with estimation error

Tran

Nguyen

Hong

2015

AEU - International Journal of Electronics and Communications

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“…The installation of TR brings capability of mitigating interference to femtocell because of its inherence of location signature-specific property [7], [8]. Note that the reversedform of CIR is utilized as a matched-filter to prefilter message-bearing signals which is represented as (13) whose optimal solution can be solved by convex optimization techniques with CVX solver [17]. This minimization problem precisely requires the CSI knowledge of femtocell only.…”

Section: System Descriptionmentioning

confidence: 99%

“…Thus, the power of all paths is harvested and the signal is compressed in the time and space domains at the receiver. Although most of previous works focus on TR ultrawideband system [6]- [10], the feasibility of TR for conventional bandwidth system has been mentioned [5], [11]- [13]. The work [5] discusses the potential of applications of TR in 3GPP LTE-A coordinated multi-point networks.…”

Section: Introductionmentioning

confidence: 99%

Time Reversal-Based Transmissions with Distributed Power Allocation for Two-Tier Networks

Tran-Ha

Hong

2015

2015 IEEE 29th International Conference on Advanced Information Networking and Applications Workshops

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Abstract-Radio pollution and power consumption problems lead to innovative development of green heterogeneous networks (HetNet). Time reversal (TR) technique which has been validated from wide-to narrow-band transmissions is evaluated as one of most prominent linear precoders with superior capability of harvesting signal energy. In this paper, we consider a new HetNet model, in which TR-employed femtocell is proposed to attain saving power benefits whereas macrocell utilizes the beamforming algorithm based on zero-forcing principle, over frequency selective channels. In the considered HetNet, the practical case of limited signaling information exchanged via backhaul connections is also taken under advisement. We hence organize a distributed power loading strategy, in which macrocell users are treated with a superior priority compared to femtocell users. By Monte-Carlo simulation, the obtained results show that TR is preferred to zero-forcing in the perspective of beamforming technique for femtocell environments due to very high achievable gain in saving energy, and the validity of power loading strategy is verified over multipath channels.

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“…TR technique [7], [8], which possesses the focalization characteristic that is equivalent to the diversity gain, can provide the solution for mentioned problems. Evaluated as one of most prominent linear precoders, TR has been employed in many applications such as green communication, ultra-wideband (UWB) and large-scale antenna systems [3], [7]- [16]. By utilizing the joint time-reversed and conjugated form of channel impulse response (CIR) for prefiltering transmit signals to exploit multipath fading effects, the most signal energy of all paths is focused in the time and space domains at the receiver side.…”

Section: Introductionmentioning

confidence: 99%

Robust Time Reversal-based Transmit Optimization for Green Heterogeneous Networks

Tran

Nguyen

et al. 2015

ElAEE

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Time reversal (TR) beamforming, considered as one of most prominent linear precoders, has showed the feasibility in conventional communications. In this paper, we propose the TR-based transmit optimization for heterogeneous networks (HetNets) where multiple femtocells apply TR precoders over frequency selective channels, with the signal-to-inference-plus-noise ratio (SINR) and interference constraints at single-antenna femtocell user devices. In multi-femtocell network environments, we exhibit that TR outperforms the well-known zero-forcing beamforming. Particularly, we focus on the practical case of imperfect channel estimation at femtocell base stations. The robust optimization methodology is hence devised by taking into account the average effect of channel estimation error (CEE) on system performance. Under the assumption of estimation error in time-varying channels, we derive the exact closed-form expressions of the desired signal, inter-symbol interference (ISI), inter-user interference (IUI), co-and cross-layer interference terms, respectively. These derivations allow us to tackle the proposed robust algorithm by convex optimization techniques. In final, numerical results are shown to confirm the validation of our proposal.

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Robustness of a time reversal system: From ultra-wide to narrow bandwidths

Cited by 5 publications

References 20 publications

Generalized analysis of MU-MISO time reversal-based systems over correlated multipath channels with estimation error

Generalized analysis of MU-MISO time reversal-based systems over correlated multipath channels with estimation error

Time Reversal-Based Transmissions with Distributed Power Allocation for Two-Tier Networks

Robust Time Reversal-based Transmit Optimization for Green Heterogeneous Networks

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