Operators are moving toward more complex commercial deployments of network infrastructure to improve network coverage and capacity. ­Smart Antennas are an increasingly important part of the network to improve capacity and, thus, operators are integrating more active electronics on tower tops and even inside the antenna radomes to better serve their customers with mobile broadband services.

4G Americas, a wireless industry trade association has published a detailed technical report, MIMO and Smart Antennas for Mobile Broadband Networks, that includes 133 figures and is encyclopedic in its 138 pages of completeness.

"The importance of MIMO and Smart Antennas for carriers and their customers should not be underestimated," stated Chris Pearson, President of 4G Americas. "In the face of growing high-speed mobile data demand in the Americas region, Smart Antennas and MIMO technology help the wireless industry get the most out of the limited amount of spectrum assets that the industry possesses."

Smart Antennas refer to adaptive antennas such as those with electrical tilt, beam width and azimuth control, which can follow relatively slow-varying traffic patterns as well as so-called intelligent antennas that can form beams aimed at particular users or steer nulls to reduce interference and general MIMO antenna schemes. The report details that 93 percent of antennas sold by one North American supplier this year have variable tilt capability, and 94 percent of those use cross-polarized elements.

"MIMO technology is increasing network performance for customers," Pearson added. "As an example from the report, an increase in capacity using MIMO is almost linear with the number of send and receive antennas, thus a 4X4 MIMO antenna configuration is capable of serving nearly twice the peak data rates as a 2X2 MIMO system."

The white paper focuses on the practical aspects of deploying Smart Antenna systems in Radio Access Systems. Additionally, since carriers are increasingly using indoor small cells and base stations for their networks, the paper addresses the practical aspects of deploying these modern base stations with their increasingly capable antennas. Diverse antennas in terminals provides another difficult challenge, also addressed in the document, as the gain of a second antenna in the terminal is shown to provide a 2dB improved forward link budget at low frequencies and over 6dB at higher frequencies.

Innovative and standardized Smart Antennas and MIMO solutions, working with small cells, heterogeneous networks and LTE help operators in their major push to keep up with the annual doubling of mobile broadband demand.