摘要 |
<p>A wireless communication system for simultaneously communicating overlapping wideband and narrowband signals. The system includes a transmitting station for embedding one or more narrowband signals (3-5) in a wideband signal (1) having a frequency spectrum encompassing the narrowband signals, and transmitting the resulting composite wideband signal (2). The system also includes a receiving station for receiving a composite wideband signal (60) and separating the embedded narrowband signal(s) (62, 63) from the wideband signal (61). In one embodiment, a cellular radiotelephone base station (35) is operable as both the transmitting and receiving station, communicating with remote subscriber units (29-31) having conventional transceivers (FDMA, TDMA and/or CDMA). The base station transmitter circuitry (10-17) includes FM and CDMA signal generators (10, 12), a combiner (15) for embedding the narrowband signal (3-5) in the wideband signal (1), and an AGC (14) and power detectors (11, 13) for controlling the narrowband signal power. The receiving circuitry includes a CDMA processing circuit having an FFT circuit (41), a threshold detector (42), a notch filter (43), and an inverse FFT circuit (44) for separating narrowband signals (62, 63) from the CDMA signal (61).</p> |