Traditional mobile radio communications system designs are largely based on the principles of engineering an independent radio link for each user. Recent developments with small cells and multiple antennas have further improved the capacity of the radio channel through high density frequency reuse. Such techniques achieve an increase in capacity (i.e. number of users and their traffic) that is linearly proportional to the number of additional antennas and the associated cells or cell sectors. However, as the volume of users and their traffic increases there is a need for a massive increase in system capacity. Examples of such massive traffic loads include stadiums and similar events attended by large crowds of connected users. In this paper we outline concepts of radio aperture synthesis and illustrate their application to a high density communications scenario. The aperture synthesis approach augments the engineering of multiple individual radio links with an arrangement of massively parallel cells (MPC). The advantage of the aperture synthesis technique for communications systems is that very high frequency reuse can be achieved and the system capacity increases approximately as the square of the number of antennas in the synthesis array.