MIMO n

In older wireless networks, a single antenna is used at the access point, and another single antenna is used at the destination or client. At times, this can give rise to problems with multipath effects. When an electromagnetic field or the signal is met with obstructions such walls or furniture or even people the wavefronts are scattered, and thus they take many paths to reach the destination. The late arrival of scattered portions of the signal causes problems such as fading, cut-out (cliff effect), and intermittent reception (picket fencing). In digital communications systems such as wireless Internet, it can cause a reduction in data speed and an increase in the number of errors.

With MIMO n(multiple input, multiple output) multiple antennas are used for wireless communications at both ends, the source (transmitter) and the destination (receiver). The antennas at each end of the communications circuit are combined to minimize errors and optimize data speed. MIMO n is one of several forms of smart antenna technology, the others being MISO (multiple input, single output) and SIMO (single input, multiple output).

Multiple-input multiple-output (MIMO n) wireless can use different waveforms on sometimes three or more transmitting antennas inputting to the channel carrying radio waves from Point A to Point B. Multiple antennas and radios (typically, two or three) also are applied to the output of the radio channel at the receiver, along with a lot of signal processing, which ideally improves range and throughput compared with simpler or traditional radio designs operating under similar conditions.

MIMO is sometimes referred to as spatial multiplexing, because it uses a third, spatial dimension - beyond frequency and time - as a carrier for information. The multiplicative effect of properly designed MIMO systems can be dramatic: As tests show, the 100Mbps barrier (application-layer throughput) in wireless LANs has been broken. Multiple Input, Multiple Output (MIMO n) technology is a wireless technology that uses multiple transmitters and receivers to transfer more data at the same time. MIMO technology takes advantage of a radio-wave phenomenon called multipath where transmitted information bounces off walls, ceilings, and other objects, reaching the receiving antenna multiple times via different angles and at slightly different times.


MIMO technology leverages multipath behavior by using multiple, “smart” transmitters and receivers with an added “spatial” dimension to dramatically increase performance and range. MIMO allows multiple antennas to send and receive multiple spatial streams at the same time. This allows antennas to transmit and receive simultaneously.

MIMO makes antennas work smarter by enabling them to combine data streams arriving from different paths and at different times to effectively increase receiver signal-capturing power. Smart antennas use spatial diversity technology, which puts surplus antennas to good use. If there are more antennas than spatial streams, as in a 2x3 (two transmitting, three receiving) antenna configuration, then the third antenna can add receiver diversity and increase range.
In order to implement MIMO, either the station (mobile device) or the access point (AP) need to support MIMO. Optimal performance and range can only be obtained when both the station and the AP support MIMO.

Legacy wireless devices can’t take advantage of multipath because they use a Single Input, Single Output (SISO) technology. Systems that use SISO can only send or receive a single spatial stream at one time.