SSZTC67 september   2015

 

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    2.     Where Can I Benefit from Having 5GHz Antenna Diversity?
    3.     So What I Need to Do in Order to Add Diversity into My Life?
    4.     Additional Resources

Oren Shani

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Realistic wireless channel models consider the impact of multipath propagation. Since a transmitted signal is subject to reflections and refraction on walls, surfaces, and so forth, the receiving node will see signals differing in phase and amplitude. Using more than one antenna allows the evaluation of different multipath scenarios to avoid or reduce the effects of fading and interferences. Diversity is used to describe a strategy for choosing the best path for transmitting or receiving an RF signal in order to maximize the possibility that a packet will be correctly received. 

Our WiLink™ 8 modules enable antenna diversity by supporting two antennas on the 5GHz band using an external Double Pole, Double Throw (DPDT) switch. This switch can be found on the following WiLink 8 modules: WL1837 and WL1807.

The WiLink 8 algorithm studies and analyzes the best signal path considering the above reasons, choosing better of two paths for transmitting and/or receiving an RF signal in order to maximize the likelihood that a packet will be correctly received, and increase throughput. The decision mechanism is based on RSSI level.

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Where Can I Benefit from Having 5GHz Antenna Diversity?

  1. In urban and indoor environments, there is no clear line of sight between transmitter and receiver. Instead the signal is reflected along multiple paths before finally being received.

    Each of these bounces can introduce phase shifts, time delays, attenuations and distortions that can destructively interfere with one another at the aperture of the receiving antenna.

  2. Antenna radiation pattern defines the variation of the power radiated by an antenna as a function of the direction away from the antenna. This power variation as a function of the arrival angle is observed at the antenna far field. Diversity between two antennas with different patterns can overcome nulls.
  3. Antenna diversity dramatically improves performance for Airplay compliance, largely helpful for those working on audio applications.

So What I Need to Do in Order to Add Diversity into My Life?

It’s very simple, you just need to have a compatible WiLink 8 module (WL1837 or WL1807) and run 'configure-device.sh' to configure the device’s wlconf file. In the script: set the number of 5GHz antennas to 2 and answer ‘yes’ when asked ‘do you support 5GHz antenna diversity?’ That’s all there is to it!