Radio unit for unsynchronized TDD multi-band operation
A radio unit for TDD multi-band operation in a wireless communication system is disclosed. The radio unit comprises a transmitting power amplifier for multi-band operation; one or more receiving amplifiers for multi-band operation and an antenna element. The radio unit further comprises one or more switch networks coupled in parallel between the power amplifier and the antenna element. Each of the one or more switch networks comprises one or more shunt switches coupled between an output of the transmitting power amplifier and a signal ground. Each of the one or more switch networks is configured to operate at a certain frequency band in transmitting or receiving mode and is controlled separately by a switching control unit based on un-synchronized TDD time slots configured according to user data traffic scheduling requirements.
1. A radio unit for un-synchronized Time Division Duplex, TDD, multi-band operation in a wireless communication system, the radio unit comprising:
a transmitting power amplifier for multi-band operation;
one or more receiving amplifiers for multi-band operation;
an antenna element; and
two or more switch networks coupled in parallel between the transmitting power amplifier and the antenna element and comprising a first filter, a circulator and a second filter;
wherein
each of the two or more switch networks comprises a shunt switch coupled between an output of the first filter and a signal ground;
each of the two or more switch networks is configured to operate at a certain frequency band in transmitting or receiving mode and is controlled separately by a switching control unit based on un-synchronized TDD time slots configured according to user data traffic scheduling requirements such that
when operating in transmitting mode, the switch network is controlled to couple the transmitting power amplifier via the first filter, the circulator, and the second filter, to the antenna element and dis-couple one of the one or more receiving amplifiers from the antenna element; and
when operating in receiving mode, the switch network is controlled to couple one of the one or more receiving amplifiers to the antenna element via the second filter and the circulator, and dis-couple the transmitting power amplifier from the antenna element by coupling said shunt switch to the signal ground.
2. The radio unit according to claim 1 , wherein the first filter in any one of the two or more switch networks is cascaded with a quarter wavelength transmission line and the circulator, wherein any one of the two or more switch networks further comprises a Single pole, double throw, SPDT, switch, wherein the shunt switch is a PIN diode and is connected between the signal ground and an interconnection of the quarter wavelength transmission line and the circulator, the SPDT switch is connected between the circulator and one of the receiving amplifiers.
3. The radio unit according to claim 1 , further comprising two or more transmitting-receiving paths coupled in parallel with the two or more switch networks, and each of the two or more transmitting-receiving paths is configured for Frequency Division Duplex, FDD, operation in a certain frequency band.
4. The radio unit according to claim 1 , wherein any two or more switch networks and/or FDD transmitting-receiving paths share one receiving amplifier.
5. A radio apparatus comprising one or more radio units according to claim 1 .
6. An electronic apparatus comprising one or more radio units according to claim 1 .
7. The electronic apparatus according to claim 6 , wherein the electronic apparatus is a radio base station or a wireless communication device for a cellular communication system.