The various types of single/multiple antenna connections are defined as follows:
- SISO – Single Input Single Output
- SIMO – Single Input Multiple Output
- MISO – Multiple Input Single Output
- MIMO – Multiple Input Multiple Output
SISO – Single Input Single Output
SISO – Single Input Single Output – is the simplest version of the radio connection in MIMO terminology. This is essentially a normal radio channel, as both the transmitter and receiver use a single antenna. There is no need for extra processing because there is no variety.
A SISO system has the benefit of being simple. In terms of the different types of diversity that may be utilized, SISO does not require any processing. The SISO channel, on the other hand, has performance limitations. The system will be more affected by interference and fading than a MIMO system, and the channel bandwidth is restricted by Shannon’s law, with the throughput being determined by the channel bandwidth and signal-to-noise ratio.
SIMO – Single Input Multiple Output
The SIMO (Single Input Many Output) variant of MIMO uses a single antenna for the transmitter and multiple antennas for the reception. Receiving diversity is another name for this. It’s frequently employed to counter the effects of fading in a receiver system that receives signals from several independent sources. It has been used for many years to fight the effects of ionospheric fading and interference with short wave listening/receiving stations.
SIMO has the benefit of being very simple to implement, but it does have certain drawbacks, such as the need for processing in the receiver. In many applications, SIMO may be appropriate, however, if the receiver is situated in a mobile device, such as a cellular handset, processing levels may be constrained by size, cost, and battery drain.
MISO – Multiple Input Single Output
Transmit diversity is another name for MISO. The identical data is redundantly broadcast from the two transmitter antennas in this scenario. The receiver is thus able to receive the best signal, which it may subsequently utilize to retrieve the data it needs.
MISO has the advantage of transferring numerous antennas and redundancy coding/processing from the receiver to the transmitter. This may be a substantial benefit in situations like cellphone UEs, saving space for antennas, and lowering the amount of processing necessary in the reception for redundancy coding. Because the reduced degree of processing demands less energy use, this has a beneficial influence on size, cost, and battery life.
MIMO – Multiple Input Multiple Output
MIMO stands for Multiple Input Multiple Output, and it occurs when both ends of a radio link have more than one antenna. Both channel robustness and channel throughput may be improved using MIMO.
It is important to be able to use coding on the channels to segregate the data from the different routes in order to fully benefit from MIMO. This involves processing, but it adds to the channel’s robustness and data throughput capability. The underlying principle behind MIMO technology is that more antennas equal greater data transfer. MIMO is a potential technique for meeting greater demands in modern wireless networks.