Spatial modulation : a spatial multiplexing technique for efficient wireless data transmission
- The need for high peak data rates with the corresponding need for significantly increased spectral efficiencies and the support for service specific QoS requirements are the key elements that drive the research in the area of wireless communication access technologies. Among the set of existing technologies, MIMO-OFDM with adaptive coding and modulation is promising candidate for future wireless systems. A few basic algorithms for multiple antenna systems and many refinements thereof have been intensively studied in the past few years. Mainly, there are three categories of MIMO techniques. First, multiple antennas can be used to improve the power efficiency by maximizing spatial diversity. The second multiple antenna algorithm exploits channel knowledge at the transmitter. In this thesis, channel information is assumed to be known only at the receiver side and no channel information exists at the transmitter side. The third type uses layered space-time approach to transmit multiple independent data streams over the antennas to increase capacity. A well-known technique is the proposed BLAST architecture. Such technique is called spatial multiplexing. There still exist several problems for a practical deployment of spatial multiplexing multiple antenna systems. One of them is the complexity of the algorithms due to seemingly unavoidable ICI. Of course, the performance of the system can be traded off against the receiver complexity, but this is not desirable. Furthermore, multiple antenna systems are known to achieve relatively good performance in idealistic channel conditions. However, the performance of these systems degrades severely under non-ideal channel conditions. A key to solving these issues is seen in the avoidance of ICI whilst maintaining the spatial multiplexing gain. The goals seem contradictory, but the feasibility is demonstrated in this thesis. The basic idea is named SM.