2 research outputs found
New Reconfigurable L-Band Digital Aeronautical Communication System
To meet an ever-increasing demand of the spectrum for communication between
aircraft and ground terminals, orthogonal frequency division multiplexing
(OFDM) based L-band (960-1164MHz) Digital Aeronautical Communication System
(LDACS) has been recently proposed as an alternative to existing narrowband
systems. However, OFDM based LDACS needs additional control signaling for time
and frequency alignment and the use of cyclic prefix and high out-of-band
emission limits the spectrum utilization efficiency to less than 50%. In this
paper, a new waveform has been proposed which offers better spectrum
utilization than OFDM without compromising on computational complexity and
interference to legacy users in L-band. It also allows transceivers to
dynamically adapt the transmission bandwidth to meet the desired quality of
service. Since the proposed waveform employs a reconfigurable multiband linear
phase filter, it is referred to as reconfigurable filtered OFDM (Ref-OFDM).
Simulation results and extensive analysis show that the proposed Ref-OFDM
offers around 40 dB better out-of-band emission than OFDM which in turn leads
to significant increase in the transmission bandwidth for a given BER and
interference constraints. The computational complexity of Ref-OFDM is slightly
higher than that of OFDM but it is significantly less than other waveforms
making Ref-OFDM an attractive waveform for next generation air-to-ground
communications. An end to end hardware prototyping of LDACS-DME coexistence is
also presented in this report
Software-defined Radios: Architecture, State-of-the-art, and Challenges
Software-defined Radio (SDR) is a programmable transceiver with the
capability of operating various wireless communication protocols without the
need to change or update the hardware. Progress in the SDR field has led to the
escalation of protocol development and a wide spectrum of applications, with
more emphasis on programmability, flexibility, portability, and energy
efficiency, in cellular, WiFi, and M2M communication. Consequently, SDR has
earned a lot of attention and is of great significance to both academia and
industry. SDR designers intend to simplify the realization of communication
protocols while enabling researchers to experiment with prototypes on deployed
networks. This paper is a survey of the state-of-the-art SDR platforms in the
context of wireless communication protocols. We offer an overview of SDR
architecture and its basic components, then discuss the significant design
trends and development tools. In addition, we highlight key contrasts between
SDR architectures with regards to energy, computing power, and area, based on a
set of metrics. We also review existing SDR platforms and present an analytical
comparison as a guide to developers. Finally, we recognize a few of the related
research topics and summarize potential solutions