State-based Spatial Multiplexing (SBSM)

State-based spatial multiplexing (SBSM) is a novel multiple input multiple output (MIMO) technology that enables MIMO operations between simple COTS radios. The SBSM technique works at the medium access control (MAC) layer; therefore, the radio only needs to be synchronized at the symbol level instead of the carrier. The technique uses a deconvolution based on an iterative Viterbi decoder to remove the effects of cascaded convolutional processes that represents the channel mixing plus a convolutional forward error correction (FEC) code. The technique uses only the symbol decisions obtained by a base-band demodulator, effectively sampled with relatively few bits of resolution. Combining MAC layer data streams of multiple observations in space provides robustness in addition to spatial multiplexing capabilities. This document presents the SBSM method, compares it to traditional MIMO methods, and concludes with simulated and measured performance for a 2times2 SBSM system.