Smart Carrier Aggregator (SCA) is advanced digital front-end software that maximizes spectral efficiency. It runs in base stations and small cells that aggregate multiple carrier components.
Rising consumer demand for mobile data over time has led to multiple phases of spectrum allocation processes such as auctions in the US. The result is fragmented spectrum on a per market basis across the globe. Carrier Aggregation (CA) — a core component now of LTE-A and of 5G as it develops — refers to using one baseband unit in a cell site to operate a network in multiple bands of spectrum. CA alone arbitrarily combines signals for downlink in a power combiner, which inefficiently allocates how to use available sub-bands and is associated with high Peak-to-Average Power Ratio (PAPR). SCA balances the load of the network across all of the aggregated spectrum in order to improve performance. It lowers PAPR, allowing the network to extend the range of any given constellation modulation.
The increase in total downlink data capacity can exceed 30% at peak demand with SCA as compared to CA without SCA even for only 2-channel CA, and the increase is higher with more complexity. SCA complies with industry standard OEMs and UEs without additional tuning steps.
The algorithm at the core of SCA uses patented, state-of-the-art signal processing techniques to analyze the structure of the individual waveforms. After analyzing the signal structure, the algorithm combines the different waveforms so that the composite signal has lower PAPR than arbitrarily combined waveforms or waveforms combined with other methods, while keeping the signals as clean and pure as when created in the core network. Less peaky and cleaner signals have better error tolerance that effectively can carry more data, which simplifies the RF stages in a base station — resulting in more energy efficient base stations that can upgrade which constellation modulation is employed.