• MSK Modulation for Multiple Access

      Magill, E. G.; Fairchild Camera and Instrument Corporation (International Foundation for Telemetering, 1977-10)
      Minimum Shift Key (MSK) is known to possess desirable qualities, such as low spectral sidelobes and dual channels quadrature in both phase and sampling time. It is also a robust signal, tolerant to considerable amplitude limiting and spectral filtering. MSK modulation of Pseudo Noise (PN) sequences can be used to effect a communication network with multiple access, which can be of either random or assigned synchronism. Such a network exhibits resistance to jamming by external signals in the form of processing gain. This approach leads to multiple access terminal designs which are coherent, with a single RF front end which is not phase locked. A particularly effective implementation outlined in this paper utilizes a Charge Coupled Device (CCD) filter matched to the PN sequence as the basic correlating device for multiple access.