Apparatus and Method for Generalized Linear MIMO Transceiver

Computing & Wireless : Wireless and Communications

Available for non-exclusive licensing


  • Robert Heath, Jr., Ph.D. , Electrical and Computer Engineering
  • Seijoon Shim , Electrical and Computer Engineering
  • Chan-Byoung Chae , University of Texas at Austin
  • Jonghyung Kwun , Samsung Electronics Company, Ltd.
  • Insoo Hwang , Samsung Electronics Company, Ltd.

Background/unmet need

The use of multiple antennas as transceivers (a combined receiver and transmitter) to improve system performance and capacity is a system called MIMO, or multiple-input multiple-output communication. There are a few different techniques used to optimize multi-user MIMO networks. One such technique is called dirty paper coding; this technique is usually very difficult to implement. Another such technique is called block diagonalization (BD). BD has the dimensionality constraint that there must be more receiving antennas than transmitting antennas. While precoding techniques exist that allow one to break this constraint, they do not take into account other-cell interference (OCI), which can seriously degrade system performance.

Invention Description

This invention is a generalized BD algorithm to transmit interference-free groups of data to different users. It not only overcomes the dimensionality constraint, but it also reduces OCI degradation. The invention is a hybrid type (linear/non-linear) precoding technique that supports multiple stream transmission in a multiuser broadcast channel. Similar to prior approaches, it assumes complete and perfect channel state information (CSI) at the transmitter.


  • Improves system throughput and capacity compared with the conventional BD system
  • Provides a means to design a MIMO precoder and decoder for downlink multiuser transmission
  • Linear/non-linear signal processing at the transmitter guarantees low complexity and low power consumption at the receiver
  • Works with advanced communication technologies such as MIMO and orthogonal frequency-division multiplexing (OFDM)


  • Does not require a global CSI at the receiver or an additional training phase
  • Has much lower receiver complexity at the expense of additional transmit complexity over BD
  • Jointly optimizes precoding and decoding matrices by iterative update

Market potential/applications

Cellular network and wireless LAN coverage enhancement