Method device base station and site for reducing the number of feeders in an antenna diversity diversity system

A method for reducing the number of feeders between a radio base station and a receiver diversity antenna arrangement that comprises at least two spaced apart antennas each adapted for reception of individual RF signals, said RF signals all being at the same frequency, said method comprising the steps of:

• converting one or more received antenna signals into a corresponding number of intermediate frequency (IF) signals by mixing with a first set of a corresponding number of reference signals;
• and,
• forwarding the signals received on all the antennas, of which one or more have been frequency converted to the base station on a single feeder.

The method recited in 17, further comprising the steps of:

• converting, at the radio base station, the IF signals into other IF signals, all on the same intermediate frequency, by mixing them with a set of reference signals and subjecting the twice frequency converted signals on the common intermediate frequency to diversity signal processing.

A receiver diversity antenna arrangement, comprising:

• at least two diversity antennas each adapted for reception of individual radio frequency (RF) signals, said RF signals all being of the same frequency;
• one or more frequency converters each adapted to convert a respective antenna signal to a respective intermediate frequency signal (IF) by mixing it with a predetermined frequency;
• a combiner for combining the signals received on all the antennas, of which signals one or more have been frequency converted, to form a composite signal which is forwarded to a radio base station on a single feeder.

A frequency converter unit for use with at least one feeder on which a plurality of signals at mutually different frequencies are transported on a single feeder, characterized by a corresponding plurality of frequency converters (55-58) for converting the signals into a corresponding number of signals all at the same frequency (RX1).

A radio base station, comprising:

• a transceiver with a plurality of frequency converters adapted to provide frequency translated signals, called diversity signals, all at the same frequency;
• and,
• means for signal processing the diversity signals in order to obtain an enhanced signal, comprising means connected to the input of the transceiver to receive from one single feeder at least one intermediate frequency signal (IF) together with either a non-frequency translated antenna signal and/or other frequency converted IF signals, and to supply said latter signals to respective ones of said frequency converters so as to provide said diversity signals.

A site comprising a radio base station (RBS), at least one tower-mounted unit (TMA) with filters and RF amplifiers, at least two antennas for providing diversity, the signals received by the antennas being RF signals which all are of the same frequency characterized by at least one frequency converter provided in the TMA and connected to one of the diversity antennas in order to convert the antenna's RF signal into an IF signal at a non-used frequency, and a combiner combining the IF signal with either a non-converted RF antenna signal and/or other converted IF signals into a composite signal which is applied to a single feeder extending between the TMA and the RBS.