IM 610179-1, Rev 02
08/25/06
Page 6
Functionality
In order to function properly, during initial set-up the downlink signal must be presented to the
EkoMini. Without the downlink signal, the unit will not operate properly.
The EkoMini is capable of automatically adjusting its own signal gain levels up to the maximum
output power levels. The EkoMini detects the downlink output power and adjusts the level for
20-dBm composite output power and continues to monitor and reset the gain as required for
proper system performance. For example, when a CDMA protocol system is being amplified,
there could be an error in set-up initially resulting from only pilot sync, and paging Walsh codes
being present on the RF carrier. The EkoMini will reduce the system gain until no signal is
received that will exceed the output power set- ting. This prevents the EkoMini from setting up
to a higher power level than actually desired if all of the Walsh codes were present. The gain
does not continually change to maintain an output power of 20 dBm (AGC) since this would
defeat and fight the benefits of power control in the system. The user may reduce or limit the
power output level by adjusting the peak power limit as described below. The user peak power
switches will set the unit's output power up to 14 dB below the maximum power output of 20
dBm; the user interface to control this feature is the peak power switches.
The EkoMini has 30 dB of gain control in the uplink and downlink signal paths. This gain is
controlled by two methods. Up to 14 dB can be con- trolled by adjusting the user peak limit
switches located behind an access plate on the side of the unit to limit the maximum output
power level. The uplink and downlink attenuators are controlled by the internal microprocessor
to adjust the maximum gain of the unit for both paths. The uplink and downlink signal paths are
adjusted to the same setting by the microprocessor unless the user offsets, reduces the gain in
the uplink signal path. The user has control to reduce the uplink gain by 6 dB, this can be used
to balance the uplink and downlink paths as well as reduce contribution of noise to the base
station receivers.
The EkoMini has a total of 30 dB of gain control in the uplink and downlink signal paths, which is
controlled by the microprocessor. The microprocessor monitors the uplink and downlink
detected signal levels and adjusts the gain to prevent overdriving the linear power amplifier
circuits.
The EkoMini monitors the downlink-detected signal and adjusts the gain to achieve rated output
power, +20 dBm. The uplink attenuation is adjusted by the microprocessor to the same gain
level. Path loss is normally equal in both directions. The microprocessor continues to monitor
the detected out- put power on both paths to prevent overdrive. Should the downlink de- tected
power increase above the desired level; the processor will reduce the gain in both uplink and
downlink paths. A subscriber unit getting very close to the rerad antenna, may cause uplink
signal overdrive. The processor will temporarily reduce the gain in the uplink (reverse) path
when uplink signal overdrive is sensed, which will reduce the coverage during this condition.
Proper placement of the rerad antenna will reduce the occurrence of this condition.
Protocol Selection
To insure proper RF power output the proper protocol must be selected this insures the
software will properly distinguish the detected RF power level. CDMA is the only protocol that
requires a different look up table/RF calibration.
Summary of Contents for EkoMini M1.9
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