Implementing a wireless LAN system for dismounted soldiers presents a number of problems that distinguish it from a commercial LAN system. Some of these unique, difficult problems include the lack of any in-place network support system, severe multi-path and fading conditions, and mobility requirements that need extended ranges of coverage. In addition to communication performance, the LAN units must be small, light weight, battery operated, and easily carried by the dismounted soldier. Perhaps the biggest challenge is getting adequate communication range in a severe channel environment. Although network relaying of data packets can solve this problem to some extent, it inherently relies on a density of nodes and/or the availability of access points. Neither of these conditions can be counted on in a tactical environment. Thus extending range point-to-point must be addressed. Range extension of a point-to-point link in a multi-path and fading environment can be achieved by adding diversity to the communication waveform. Current research in this area is focused on the use of antennas to obtain spatial diversity. Because of the mobility of the dismounted soldier, additional diversity techniques must be used in combination with the spatial diversity to achieve operational reliability. For this study we propose multiple antenna inputs in combination with a frequency hopping waveform to achieve viable range extension in a foliage environment. The range performance is maximized with respect to the operational environment by the adaptive selection of signal combining and forward error correction coding. In this proposal we outline a study to show the benefits of this approach. The communication waveform developed in this study will provide an adaptable solution to achieving range extension for a dismounted soldier LAN in a severe environment. The waveform design will make use of COTS circuits and facilitate a low cost solution. Potential commercial applications that could benefit from a LAN with extended point-to-point range include police, fire, and search and rescue.
