Abstract: A method and apparatus are provided for connecting a telephone subscriber to the public switched telephone network ("PSTN"), where a physical connection is not available while utilizing conventional telephony subscriber terminals. The connection is provided using a wireless telecommunications system adapted with a gateway collection of lines and a switch between the wireless system and the PSTN. When a call is to be made, the wireless system sends a predetermined access number to identify the caller as a gateway caller. Thereafter, a connection is made between the wireless subscriber and a dedicated PSTN line. The method includes providing a gateway access code to the public switch to obtain a trunk line and thereafter, utilizing the normal call progression cues provided by the PSTN, such as a busy signal and dial tone. The destination telephone number dialed as DTMF is then sent over a designated voice channel by the transceiver, and the connection is made by the PSTN.

Abstract: A cellular subscriber modem for receiving CCITT-type quadrature amplitude modulated (QAM) signals. The cellular modem includes a novel symbol detector that converts received symbol information to polar notation. The detector's constellation thresholds include a circular threshold having a radius greater than the magnitude of the innermost symbols, but less than the magnitude of the outermost symbols, and radially spaced thresholds, which further discriminate between the outermost symbols. As a result, special cellular-compatible modem equipment need not be connected between the public-access switched telephone network and the computer equipment at the other end, which means that a CCITT-compatible cellular subscriber modem can then be treated as any other type of CCITT-modem. The detector may be implemented in the software of a standard modem processor, or as several analog comparator circuits.

Abstract: A cellular-telephone transmitter (10) employs a vector modulator (14). An integrating circuit (52) generates the integral of the message signal and applies it to circuitry (54, 56) for generating in-phase and quadrature modulation signals representing the cosine and sine, respectively, of the integrating-circuit output. The vector modulator (14) produces the desired FM signal by adding together quadrature and in-phase versions of a carrier in proportion to the values that the quadrature and in-phase modulating signals represent.