Weifang Goertek Electronics Co. Ltd GBDA60 User Manual

Equipment with power control capability optimizes the output power in a link 
with LMP commands 

. 

It is done by measuring RSSI and report back if the power 

should be increased or decreased. 
 
Note that power class 1 must not be used for sending packets from one device 
to another if the receiving side of a connection does not support the necessary 
messaging for power control of the sending side (i.e. RSSI measurements and

 

related messages). In this case, the transmitter should comply with the rules of 
a class 2 or class 3 transmitter.

 

 
Also note that if a class 1 device is paging or inquiring very close to another 
device, the input power could be larger than the requirement in 4.5 Maximum 
usable level. This can cause the listening device to fail to respond. It is therefore 
useful to page and inquireas well using transmission according to power 
class 2 or class 3. 
 

The Modulation is GFSK (Gaussian Frequency Shift Keying) with a BT=0.5. 
The Modulation index must be between 0.28 and 0.35. A binary one is represented 
by a positive frequency deviation, and a binary zero is represented by a 
negative frequency deviation. The symbol timing shall be better than ±20 ppm.

 

 

 

For each transmit channel, the minimum frequency deviation (Fmin = the 
lesser of {Fmin+, Fmin-}) which corresponds to 1010 sequence shall be no 
smaller than ±80% of the frequency deviation (fd) which corresponds to a 
00001111 sequence. 
In addition, the minimum deviation shall never be smaller than 115 kHz. The