Sumitomo Electric Industries, Ltd. (TOKYO:5802) (ISIN:JP3407400005)
has successfully developed a remote radio head (RRH) used in a cellular
base station for Long Term Evolution (LTE) service, the next generation
mobile communication. With this RRH, Sumitomo Electric has realized a
wireless output power of 80 W at 2.1 GHz at a low power consumption of
less than 270 W, achieving the industry's highest class efficiency.
RRH for LTE Base Station (Photo: Business Wire)
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?Background of the RRH development?
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The next generation wireless broadband systems, such as LTE and
WiMAX networks, have recently come into practical use. In these
systems, a new design scheme has been increasingly implemented,
where the wireless transceiver known as RRH is separated from the
base station to be placed beneath the antenna. This scheme has now
become the mainstream in this field for the following advantages:
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-Locating the RRH closer to the antenna prevents the power loss
caused while transmitting through a long cable. Consequently, the
amplifier output to the antenna is lowered, and the total power
consumption by the RRH is reduced.
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-Conventionally, the base station main equipment needs to be
installed near an antenna. With the independent RRH, this is not
required, effectively increasing the options for the installation.
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In response to this trend, Sumitomo Electric developed the RRH for a
WiMAX base station in 2010. The Company has also developed this year a
new RRH for an LTE base station by incorporating a higher efficiency
power amplifier and the original pre-distorter. This newly developed RRH
demonstrates a wireless output of 80 W at a lower power consumption of
less than 270 W, achieving an improved efficiency of more than 30%.
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?Features of the newly developed RRH?
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1.
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High efficiency power amplifier utilizing Envelop Tracking technique
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In the orthogonal frequency division multiplexing (OFDM) system,
which is applied for LTE and WiMAX wireless communication standards,
the modulated signal amplitude fluctuates largely with time. Envelop
Tracking technique controls supply voltage to the amplifier in
response to the fluctuation, thus significantly improving the
efficiency of the power amplifier.
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2.
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Reduced power consumption, body size and weight
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The combined use of a high efficiency amplifier and the original
pre-distorter successfully reduces power consumption by the RRH.
This improvement minimizes the energy consumed by the entire system
as well as operational costs spent by communications companies. This
is also beneficial for base stations, which can serve for a longer
time after a power outage.
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Furthermore, its smaller and lighter (less than 20 kg) body eases
the installation, allowing the antenna pole or tower to be
simplified.
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3.
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Multi-carrier System
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The RRH employs a multi-carrier system to support multiple users in
response to the increase in the number of subscribers.
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4.
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Optical interface
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The base station employs the industry-standard Common Public Radio
Interface (CPRI).
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Based on the specifications of this product, Sumitomo Electric
intends to continue its development efforts for the early
commercialization of the RRH for LTE base stations. The Company has
also created a web site featuring the RRH with the aim of
introducing its RRH lineup to the global market.
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Sumitomo Electric RRH Site: http://global-sei.com/rrh/
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* "WiMAX" is a trademark or registered trademark of the WiMax Forum in
the United States and some other countries.
Photos/Multimedia Gallery Available: http://www.businesswire.com/cgi-bin/mmg.cgi?eid=6762859&lang=en
