摘要:
A digital receiver (200) and transmitter (300), wherein the digital receiver includes a plurality of antennas (202) for receiving uplink radio frequency signals; a plurality of analog to digital converters (210) for converting the received radio frequency signals into digital signals; a switched digital down converter (214) for down converting one of the digital signals to a baseband IF signal; and a channel processor (228) for recovering one of a plurality of communication channels contained within the baseband IF signal.
摘要:
A multiple access digital up converter/modulator includes selectors (1606, 1608) having inputs (1602, 1604) and outputs coupled to first and second interpolating filters (1610, 1626). The output of the first interpolating filter is selectively coupled to a first mixer (1612) and a first adder (1622), the first adder also receiving a first phase value and the output is coupled to a first phase accumulator (1616) the output of which is coupled to a first sinusoid generator (1614) and selectively coupled to a second sinusoid generator (1630). The output of each of the first and second mixers are selectively coupled to an output adder (1634) and to inputs of the first and second mixers. The output of the second interpolating filter (1626) is selectively coupled to a second mixer (1628) and a second adder (1638), which also receives a second phase value and the output of which is coupled to a second phase accumulator (1640) the output of which is selectively coupled to the second sinusoid generator. The output of each of the first and second mixers are selectively coupled to an output adder (1634).
摘要:
Generally stated, an apparatus and method for routing a digitized radio frequency (RF) signal 140-143 to a plurality of paths is described herein. In accordance with a first preferred embodiment, the apparatus comprises a digital upconverter/modulator (DUC) 125, 129 coupled to a scaling and switching network 100N which is comprised of, at minimum, a first, second, third and fourth digital switch, and a first, second and third adder. Within the scaling and switching network 100N, the first digital switch is responsive to the DUC 125,129. The first adder is responsive to the first and second digital switches, while the second adder is responsive to the third and fourth digital switches. Finally, the third adder is responsive to the first and second adders.
摘要:
A multi-channel digital transceiver (400) receives uplink radio frequency signals and converts these signals to digital intermediate frequency signals. Digital signal processing, including a digital converter module (426), is employed to select digital intermediate frequency signals received at a plurality of antennas (412) and to convert these signals to baseband signals. The baseband signals are processed to recover a communication channel therefrom. Downlink baseband signals are also processed and digital signal processing within the digital converter module (426) up converters and modulates the downlink baseband signals to digital intermediate frequency signals. The digital intermediate frequency signals are converted to analog radio frequency signals, amplified and radiated from transmit antennas (420).