3G Americas, a wireless industry trade association representing the GSM family of technologies including LTE, announced that it has published an educational report titled, MIMO Transmission Schemes for LTE and HSPA Networks as a tool to increase awareness of smart antenna systems – also known as multiple-input multiple-output (MIMO) technology – and help guide their deployments in HSPA and LTE networks within 3GPP’s specifications and technology standards. The 3GPP evolution continues to be the leader in standardizing the most advanced forms of multiple-input multiple-output (MIMO) antennas.
Smart antenna, or MIMO, technology is commonly defined as, the use of two or more unique radio signals, in the same radio channel, where each signal carries different digital information, or two or more radio signals that use beam forming, receive combining and spatial multiplexing (SM). Relative to a traditional 1x1 antenna system, a 2x2 MIMO system is expected to deliver significant cell throughput gain.
The MIMO Transmission Schemes for LTE and HSPA Networks report provides an overview and detailed information of the current and emerging MIMO techniques that significantly increase the performance of HSPA and LTE networks.
“Smart antenna technology has arrived and will be a vital part of mobile broadband communications,” stated Pantelis Monogioudis, Ph.D, of Alcatel-Lucent LTE-Advanced Technology Strategy. “It is an exciting time for smart antenna technology as 3GPP has provided the leading technical standards for MIMO that the industry will utilize to improve the capabilities of mobile broadband.”
MIMO was first standardized in 3GPP Release 6 (Rel-6), and was further developed in Rel-7 with spatial multiplexing for HSPA+ using Double Transmit Adaptive Array (D-TxAA). As the report highlights, the use of multiple antennas at both transmitter and receiver allows:
- Substantial increase in peak data rate
- Significantly higher spectrum efficiency, especially in low-interference environments
- Increased system capacity (number of users)
Based on simulation results presented in the report, it was shown that the relatively simple MIMO transmission scheme based on 2x2 closed-loop SM, at low user equipment (UE) speeds, can increase by 20 percent the downlink (DL) sector spectral efficiency relative to a single antenna transmission, as well as increase the cell edge efficiency by approximately 35 percent. More advanced antenna configurations can provide benefits that are significant for users that are receiving a strong signal as well as cell edge users.
The 3GPP Rel-8 LTE specifications, completed in March 2009, included the most advanced forms of MIMO of any standard in the industry, and now, 3GPP is studying even more advanced MIMO enhancements for inclusion in 3GPP Rel-9 and Rel-10 for LTE-Advanced.
The white paper, MIMO Transmission Schemes for LTE and HSPA Networks, was written by members of 3G Americas, and is available for free download on the
3G Americas website here.
