Decoupled downlink reception and uplink reception in a mixed licensed carrier and unlicensed carrier wireless communication system
摘要
說明書
It is also expected that deployments of future cellular communications networks will be characterized by a mixture of user-deployed and operator-deployed radio access nodes with different power levels using frequencies ranging from below 1 GHz to tens of gigahertz (mmWave). The different radio access nodes are expected to provide services for very different types of traffic and natively support Device-to-Device (D2D) communications.
Recent studies on electromagnetic field exposure show that, in order to be compliant with applicable exposure limits at frequencies above 6 GHz, the maximum transmit power in the uplink may have to be several decibels (dB) below the power levels used for current cellular technologies. Since the transmit power has an important impact on uplink coverage, in particular for sounding over a non-precoded channel, a pragmatic approach is to use DUDe where the uplink of a UE is provided via a connection with one radio access node on a lower frequency (e.g., a carrier frequency that is less than 6 GHz) with a better link budget and a downlink of the UE is provided via a connection with another radio access node on a higher carrier frequency (e.g., a carrier frequency that is greater than or equal to 6 GHz). In other words, in a mmWave network, associating a UE to a mmWave small cell in the downlink and to a sub-6-GHz macro cell in the uplink utilizing DUDe is beneficial.
