which known and different signals are transmitted from each antenna. These signals provide information about the transmission channel (so-called Channel State Information or CSI), and with this information the receiver can compute the singular values that are used to decode the remainder of the data packet. The increased capacity of MIMO radio can be used to achieve a higher data rate or to increase link robustness or range for a given data rate. The IEEE 802.11n specification (described in the Section "MIMO and Data Chapter Four Rates to 600 Mbps (802.11n), p. 165") will use MIMO to increase the PHY layer data capacity of the 802.11a/g radio from 54 Mbps to in excess of 200 Mbps. Space time block coding (STBC) is a related technique which combines space and time diversity to increase the robustness or range of an RF link. STBC breaks the transmitted data into blocks and transmits multiple time- shifted copies of each block of data from each transmitting antenna to the receiving antenna. STBC is thus a Multi-Input Single-Output (MISO) technique (see Figure 4-37), although multiple receiving antennas can further improve performance. Near Field Communications Introduction Near field communications (NFC) is a very short range radio frequency communications technology that has been extensively developed for use in RF identification (RFID) tags and other smart labelling applications. These applications have typically employed a RF carrier frequency of 13.56 MHz, which is internationally allocated as an unlicensed ISM band. NFC is distinct from so-called far field RF communication used in personal area and longer range wireless networks, since it relies on direct magnetic field coupling between transmitting and receiving devices. There are two types of NFC devices, active and passive, which operate quite differently. Passive devices do not have an internal power source, but derive their power from an active initiating device by inductive coupling. A passive device also does not transmit data by generating a magnetic fi