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Adjacent Channel Leakage Ratio
As wireless demand has been increasing dramatically,
the allocated frequency spectrum is getting crowded.
The wireless infrastructure requires much more significant
data capacity and bandwidth to deliver IP services to
more subscribers and mobile devices. While transmitting
signals through an over-air interface, the power leaks
from a transmitted signal into adjacent channels can
interfere with the transmission in the adjacent channels
and impair overall radio system performance. ACLR
is a key standards-compliant spectrum measurement
designed for wireless radio systems such as 3GPP 5G,
LTE, and W-CDMA. It characterizes the ratio of modulated
signal power versus power emitted or leaked into the
communication system's adjacent channels. The ability to
vary channel bandwidths and adjacent channel spacing
is required within the context of various communication
protocols
(Figure 3).
Figure 3: Adjacent Channel Leakage Ratio. (Source: Xilinx)
Xilinx PRODUCT SPOTLIGHT
XILINX ZYNQ
®
ULTRASCALE+
™
RFSOC
ZCU111 EVALUATION KIT
s
SNR and ENOB are standard parameters used to
characterize and evaluate data converters when set
up with a sinusoidal input over full Nyquist bandwidth.
However, these and other legacy metrics are deprecated
for direct-sampling applications. The RF data converters
employed in such designs are not required to operate
over the full Nyquist bandwidth. Instead, the NSD, IM3,
and ACLR parameters are more relevant to evaluating
devices used in direct-sampling designs.
Xilinx's Zynq UltraScale+ RFSoC family of devices,
featuring integrated multichannel direct-sampling
RF-ADCs, is available to fulfill the most demanding
RF processing requirements, including the
implementation of a complete software-defined
radio (SDR) on a single device.
CONCLUSION
