Special issue on broadband mobile communications at very high speeds

Pingzhi Fan,H Vincent Poor,P Takis Mathiopoulos,Erdal Panayirci

doi:10.1186/1687-1499-2012-279

Abstract

Future mobile communication systems aim at providing very high-speed data transmission, even under very high mobility scenarios such as high speed wheel-track trains (up to 574.8 km/h test speed or 380 km/h commercial speed), maglev trains (up to 581 km/h test speed or 431 km/h commercial speed), airplanes (about 4001000 km/h commercial speed), guided missiles (about 980–20,000 km/h) or spacecraft (at least 28,440 km/h to remain on an earth orbit, at least 40,320 km/h to leave earth). A related and particularly important commercial application is the strong worldwide increasing demand for broadband wireless communications in high speed railways to provide information and onboard entertainment services to passengers, train control, train dispatch, train sensor status transmission, video surveillance, etc. Consequently, increasing demand on data rates to support broadband high speed communication systems in the presence of frequency selective fading channels with very high mobilities has resulted in research on designing computationally efficient yet faster new algorithms for channel estimation, equalization and detection, as well as fast handover, location update, modeling of rapidly time-varying channels, fast power control and dedicated network architectures, etc. Orthogonal frequency-division multiplexing (OFDM) is becoming a backbone structure of such systems, being standardized as the IEEE's 802.16 family better known as Mobile Worldwide Interoperability Microwave Systems for Next-Generation Wireless Communication Systems (WiMAX) and by the Third-Generation Partnership Project (3GPP) in the form of its Long-Term Evolution (LTE) project. Both systems employ orthogonal frequency division multiplexing/multiple access (OFDMA) as well as a new single-carrier frequency-division multiple access (SC-FDMA) format. To promote the IEEE 802.16 standards, recently, a high mobility feature has been introduced (IEEE 802.16 m) to enable mobile broadband

Highlights

Future mobile communication systems aim at providing very high-speed data transmission, even under very high mobility scenarios such as high speed wheel-track trains, maglev trains, airplanes, guided missiles or spacecraft
Among the five papers dealing with channel modeling and estimation, two papers are concerned with channel estimation methods, namely, "Doubly Selective Channel Estimation for Orthogonal Frequency Division Multiplexing (OFDM) Modulated Amplify-and-Forward Relay Networks Using Superimposed Training” (Zhang Han), and "Channel Estimation in Orthogonal frequency-division multiplexing (OFDM) Systems Operating under High Mobility Using a Wiener Filter Combined with a Basis Expansion Model” (Ke Zhong, et al.)
The former proposes a novel superimposed training (ST) strategy that allows the destination node to separately obtain the channel information of the source-relay link and the relay-destination link, from which the optimal ST signals are derived by minimizing the channel mean-square-error; and the latter proposes to combine the Wiener filter (WF) with a basis expansion model (BEM) to deal with channel estimation in various mobile environments, especially in high speed cases