BeiDou AltBoc Signal is Being Tracked


New phase 3 satellites of Chinese BeiDou satellite system have several new signals. ICD for B1C and B2A signals are available, while for the other signal(call it B2B) is not. We were able to track the signal that is on 1207140000 MHz frequency on BeiDou's satellites #32,33,34. Now we see that this signal is available on all recently launched BeiDou phase 3 satellites and we track it successfully.

This B2B signal plus B2A signal together form altBoc(10,15) signal on 1191795000 MHz (call it BaltBoc). Assuming, that BOC parameters of this signal are similar to Galileo's, we managed to track it. Below graphs show BeiDou and Galileo (BaltBoc and altBoc) discriminator curves. They look identical.

Red and Blue - I of B2A(E5A) and B2B(E5b) sub-signals.
Purple and Yellow - Q of B2A(E5A) and B2B(E5b) sub-signals (their sum is zero).
Green and Aqua - dI (early-minus-late) of B2A(E5A) and B2B(E5b) sub-signals.

Next graphs show satellite #27 path: range-minus-phase (iono-free), energy and elevation.

Legend:
C/A - B1
P1 - BaltBoc
P2 - B2B
L2C - B3
L5 - B2A
L1C - B1C

Tracking of B2B and BaltBoc signal will be available on most of our receivers with 3.7.4 firmware or higher, which should be released by Mid October 2018.