Joint Carrier Allocation and Beamforming for cognitive SatComs in Ka-band (17.3–18.1 GHz)

Abstract

Abstract-Herein, we study the spectral coexistence of Geostationary (GEO) Fixed Satellite Services (FSS) downlink and Broadcasting Satellite Services (BSS) feeder links in the Ka-band (17.3 − 18.1 GHz) which is primarily allocated for BSS feeder links. Firstly, a novel cognitive spectrum exploitation framework is proposed in order to utilize the available band efficiently. Subsequently, based on the interference analysis carried out between these systems, two cognitive approaches, namely Carrier Allocation (CA) and Beamforming (BF), are investigated under the considered framework assuming the availability of an accurate Radio Environment Map (REM). The employed techniques allow the flexibility of using additional shared carriers for the FSS downlink system along with the already available exclusive carriers (19.7 − 20.2 GHz), thus increasing the overall system throughput. It is shown that a significant improvement in the per beam throughput as well as in the beam availability can be achieved by applying CA and BF approaches in the considered scenario.

Spectrum awareness and exploitation for Cognitive Radio Satellite Communications

“…This flexibility enhances the total per beam throughput by 162.6% in comparison to the per beam throughput achieved when using exclusive bands only. Moreover, the beamforming approach provides additional 7.39% gain in the per beam throughput over the case without BF [17]. The overall additional spectrum when using CA and BF, with respect to the exclusive band case, is equal to 180%.…”

“…Carrier allocation (CA) and beamforming (BF) techniques have been analyzed and implemented for spectrum exploitation [17], [18]. The CA module assigns carriers to each user based on two main objectives: i) maximizing the overall throughput; and ii) maximizing the availability.…”

Cognitive spectrum utilization in Ka band multibeam satellite communications

“…The latter leads to a smaller size cognitive zone and is investigated with promising results in [6], [12].…”

“…In Scenarios A and B, a receiver beamformer can be designed in order to detect the harmful FS signals so that the satellite terminal can avoid using the harmful FS carriers, or to enhance the SINR by mitigating the interference using side-lobe cancellation [12].…”

“…Because no cooperation between the FS and FSS systems are foreseen so far, this context requires special consideration and possibly a new enabling technology to make the beamforming context work. Successful application of beamforming in interference mitigation for Scenarios A and B is studied in [6], [12].…”