Sensing for spectrum sharing in cognitive LTE-A cellular networks

Abstract

In this work we present a case for dynamic spectrum sharing between different operators in systems with carrier aggregation (CA) which is an important feature in 3GPP LTE-A systems. Cross-carrier scheduling and sensing are identified as key enablers for such spectrum sharing in LTE-A. Sensing is classified as Type 1 sensing and Type 2 sensing and the role of each in the system operation is discussed. The more challenging Type 2 sensing which involves sensing the interfering signal in the presence of a desired signal is studied for a single-input singleoutput system. Energy detection and the most powerful test are formulated. The probability of false alarm and of detection are analyzed for energy detectors. Performance evaluations show that reasonable sensing performance can be achieved with the use of channel state information, making such sensing practically viable.

Licensed Spectrum Sharing Schemes for Mobile Operators: A Survey and Outlook

“…In the case that national roaming is not a desirable solution for the competitive MNOs, other types of sharing such as mutual renting and LSA-like approaches can prove beneficial. In this case, the MNOs can leverage their own existing infrastructure Mutual Renting (V-C-2-a) [115], [126][127] Spectrum Pooling (V-C-2-b) [80], [82], [84][85], [97] Inter-operator Spectrum and RAN Sharing (V-C-1)…”

“…In [127], the authors apply cognitive sensing through energy detection as a coordination technique (which is performed by UE or any other sensing equipment) between two MNOs. The primary-secondary priority right of access to the shared bands is considered as spectrum sharing policy between participating MNOs.…”

“…When two BSs, belonging to different MNOs, transmit through a single PRB during one TTI, the Physical Downlink Control Channel (PDCCH) [128] of two BSs which is transmitted via specific Orthogonal Frequency Division Multiplexing (OFDM) symbols of that PRB, will overlap in the same symbols. This problem can be solved via either synchronisation between the BSs, or cross-carrier scheduling (which means that each MNO must have a dedicated spectrum in parallel with the shared spectrum) ,or applying LTE Release 11 feature, e.g., [127] in which, the control data can be transmitted in any OFDM symbol. Given the challenges of the deployment, this approach can be deployed as a complementary trend in conjunction with other approaches.…”

“…user throughput outside of the exclusion zone (where incumbent users do not exist), and 10% improvement in average user throughput within the exclusion zones, with power reduction and downtilt "RED Technologies" [158], "ADEL" [148] Radio Environment mapping M ore dynamic and accurate spectrum opportunity detection Project ongoing are not utilised by the actual license holder, on the condition that coordination between sharing parties is performed properly in order to avoid interference. However, due to the user diversity and traffic correlation among operators, it is not always possible to achieve constant capacity gains [117], [126], [127], [164].…”

On simultaneous sensing and reception for cognitive LTE-A systems

“…1. In [9], we discussed the possibility of long-term spectrum sharing and short-term spectrum sharing, respectively. Long-term sharing refers to the case where sharing is applied only in the time domain and the transmission phase is of the order of several thousands of radio frames.…”