I have a Quectel RM502Q-AE module connected to an Poynting MIMO-3-17 antenna. The antenna has 4 cables for cellular (Main 1, Div 1, Main 2, Div 2). My carrier uses the 1800MHz and 3500MHz band for 5G, which are called MHB and UHB in the modems hardware specs. The modem has 4 antenna connectors (ANT0-3) which are described as followed:
- ANT0: MHB TRX & UHB PRX MIMO
- ANT1: MHB DRX MIMO & UHB DRX MIMO
- ANT2: MHB PRX MIMO & UHB TRX
- ANT3: MHB DRX & UHB DRX & GNSS L1 RX
I have not yet fully understood how MIMO works in detail and failed to answer the following two questions during my research:
- Does it matter in what order I connect the antenna cables to the modem? If yes, what is the optimal order? I would guess Main1 → ANT0, Div1 → ANT1, Main2 → ANT2, Div2 → ANT3. Is this correct, if yes, why?
- If I would substitute the cellular antenna cable on ANT3 with a GPS antenna, would I have to expect a loss in signal quality or speed? If yes, why, since the DRX part seems to be redundant?
I would be very grateful if someone could shed some light into the shadows.