Issue link: https://read.uberflip.com/i/1423190
LoRa Alliance ® Whitepaper Page 20 of 49 LoRaWAN ® Gateways Radio Coexistence Issues and Solutions Copyright ©2021 LoRa Alliance, Inc. All rights reserved. www.lora-alliance.org This performance can be achieved thanks to cavity duplexers. 3.3.6 REQUIRED ISOLATION BETWEEN ANTENNAS Depending on the minimum requirement considered (i.e. ACLR, operating band unwanted emissions, and moreover spurious emissions when colocated), we can see a huge variation of out-of-band emissions requirements in the unlicensed band. In a real use case, an LTE BS embeds a cavity duplexer, which significantly reduces the out-of-band spurious emissions. The performance of the LTE BS is then very close to the ACLR requirement at the edge of the UTRA DL band but meets colocated spurious emissions at 20MHz offset from the UTRA DL band. According to Report ITU-R SM.2421-0 (see [9]), a typical LTE BS output spectrum, without external filtering (Tx1 and Tx3), is as follows: Figure 19: Typical emissions from an LTE800 BS without external filter According to Report ITU-R SM.2421-0 (see [9]), a typical LTE BS output spectrum, including external cavity filter, is as follows: Figure 20: Typical emissions from an LTE800 BS with external filter