Cloud Transmission: System Performance and Application Scenarios

Abstract

Cloud Transmission (Cloud Txn) System is a flexible multi-layer system that uses spectrum overlay technology to simultaneously deliver multiple program streams with different characteristics and robustness for different services (mobile TV, HDTV and UHDTV) in one RF channel. The transmitted signal is formed by superimposing a number of independent signals at desired power levels, to form a multilayered signal. The signals of different layers can have different coding, bit rate, and robustness. For the top layer, system parameters are chosen to provide very robust transmission that can be used for high speed mobile broadcasting service to portable devices. The bit rate is traded for more powerful error correction coding and robustness so that the Signal to Noise Ratio (SNR) threshold at the receiver is a negative value in the range of -2 to -3 dB. The top layer is designed to withstand combined noise, co-channel interference and multipath distortion power levels higher than the desired signal power. The lowerlayer signal can be DVB-T2 signal or other newly designed system to deliver HDTV/UHDTV to fixed receivers. The system concept is open to technological advances that might come in the future: all new technologies, BICM/Non Uuniform-QAM, rotated constellations, Time Frequency Slicing or MIMO techniques can be implemented in the Cloud Txn lower (high data) rate layer. The main focus of this paper is to thoroughly describe the performance of this newly presented Cloud Transmission broadcasting system.

Sum Utilization of Spectrum with Spectrum Handoff and Imperfect Sensing in Interweave Multi-Channel Cognitive Radio Networks

“…The unlicensed users cannot access the licensed bands, making the bands under-utilized [6,10]. Spectrum allocation flexibility and spectrum utilization efficiency can be achieved with different proposed technologies, such as LTE-WiFi aggregation (LWA) [11], operations in millimeter-wave band [12], LTE over the unlicensed band (LTE-U) [13], multicasting [14,15], layer-division multiplexing [14,16], ultra-dense small cells in Sustainability 2018, 10, 1764 3 of 18 5G architecture [17], non-orthogonal multiple access (NOMA) [18][19][20], and software-defined cognitive radio network (SD-CRN) [21][22][23][24][25].…”

Error propagation in the cancellation stage for a multi-layer signal reception

“…Additionally, regarding the transmitter implementation, this approach does not present much extra computational cost. The creation of a two layer signal may be as simple as implementing a weighted sum of both layers as demonstrated in [7]. Nevertheless, it must be borne in mind that in order to allow the frequency domain cancellation at the receiver side and for hardware simplicity, both layers should share the same FFT size, in-band pilots and Guard Interval (GI) value.…”

“…The theoretical upper performance bounds for the cancellation algorithm have already been given in [7]. However, there has not been included a detailed analysis of the possible errors in the upper layer cancellation and the resulting error propagation.…”

LDM Versus FDM/TDM for Unequal Error Protection in Terrestrial Broadcasting Systems: An Information-Theoretic View

“…P OWER-based Layer-Division Multiplexing (LDM) has been recently proposed as a key technology for nextgeneration digital terrestrial television (DTT) standards to simultaneously provide fixed and mobile services in the same radio frequency (RF) channel [1], [2]. LDM may outperform traditional approaches as Frequency-Division Multiplexing (FDM) and Time-Division Multiplexing (TDM) by multiplexing the fixed and mobile information layers at different power levels across all available time-frequency resources.…”