2×2 MIMO vs. 4×4 MIMO Antenna for 4G 5G Modems

What Is a MIMO Antenna?

MIMO, short for Multiple Input Multiple Output, is a wireless communication technology that uses multiple antennas for simultaneous transmission and reception. In mobile modem routers, MIMO antennas improve data throughput, signal stability, and overall link reliability, especially in challenging signal conditions such as outdoor and industrial environments.

2×2 MIMO versus 4×4 MIMO Antenna

MIMO antennas are available in various configurations, including 2×2, 4×4, 8×8, and massive MIMO. The first number refers to the number of transmitters, and the second number refers to the number of receivers in the MIMO system. In mobile router deployments, 2×2 and 4×4 MIMO are the most widely used configurations. The following section focuses on comparing these two MIMO types to highlight their technical differences and practical implications.

In general, a 2×2 MIMO antenna is sufficient for most 4G LTE (CAT1/4/6) mobile modems and cost-sensitive deployments, especially in rural or low-load environments.

A 4×4 MIMO antenna is best suited for LTE-Advanced (CAT16 and higher) and 5G-NR mobile modems that actively support higher-order MIMO. In contrast, in poor coverage or low-SINR conditions, antenna gain and installation quality often matter more than the number of MIMO layers.

The table below provides a quick reference for selecting between 2×2 and 4×4 MIMO antennas based on common deployment scenarios and network conditions.

MIMO and Carrier Aggregation On Mobile Modem

The advanced 4G-LTE and 5G-NR mobile modems use both MIMO and Carrier Aggregation technologies to enhance cellular signal quality, improve data throughput, and maintain connection stability.

Below is a basic introduction to the commonly used mobile modems on our router models. They can natively support MIMO layers and auto-activate carrier aggregation. Their technology grades below might have a deviation value according to different modem versions.

Remarks:

1. MIMO and carrier aggregation are implemented on different carrier frequency bands and do not work peer-to-peer.
2. MIMO system is downward compatible. For example, 4×4 MIMO could also support 4×2 and 2×2 MIMO arrangements.
3. CAT6/12 modems use nonequivalent 4×2 MIMO layers on download links. 4×2 MIMO refers to 4x transmitters and 2x receivers. CAT1–4 modems use the main and diversity antennas instead of MIMO.

MIMO or CA – Which is Preferred?

The mobile modem prefers carrier aggregation to increase bandwidth and data rates. It also relies on MIMO antennas’ spectral efficiency and spatial separation to improve signal quality and data rates.

MIMO is an antenna technology that utilizes more efficient spatial multiplexing to improve data rates. It uses multiple antennas to transceive parallel data streams. MIMO antennas improve mobile signal quality by minimizing the impact of multipath fading through antenna diversity and benefiting from beamforming to receive a more robust signal.

Carrier aggregation is a mobile modem technology that combines multiple frequency bands from mobile carriers and generates a large aggregated data pipe to improve bandwidth and data throughput.