System and method for TDD-FDD duplexing in a radio architecture
A reconfigurable TDD-FDD multiplexer operates in a TDD mode and a FDD mode. The TDD-FDD multiplexer includes an interdigital quadruplexer in series with a one-pole three-throw RF switch. The interdigital quadruplexer includes of two V-band filters, connectable to a transmitter and a receiver, respectively, for TDD mode duplexing, and two E-band filters, connectable to a transmitter and a receiver, respectively, for FDD mode duplexing. The E-band filters include an E-band transmitting filter that passes an E-band transmitting frequency band, and an E-band receiving filter that passes for an E-band receiving frequency band offset from the E-band transmitting frequency band. Switching between the V-band receiving filter and V-band transmitting filter enables TDD duplexing functionality at V-band frequencies. Switching to the two E-band filters enables FDD duplexing functionality at E-band frequencies.
1. A multiplexer comprising:
a first band pass filter having a first frequency passband and a first port for coupling to a transmitter for the first frequency passband;
a second band pass filter having a second frequency passband and a first port for coupling to a transmitter for the second frequency passband;
a third band pass filter having a third frequency passband that is offset from the second frequency passband, and a first port for coupling to a receiver for the third frequency passband;
a fourth band pass filter having a fourth frequency passband, and a first port for coupling to a receiver for the fourth frequency passband; and
a switch for coupling an antenna to:
when operating in a time division duplexing (TDD) mode:
a second port of the first band pass filter in a first switch position during signal transmitting; and
a second port of the fourth band pass filter in a third switch position during signal receiving; and
when operating in a frequency division duplexing (FDD) mode:
both a second port of the second band pass filter and a second port of the third band pass filter in a second switch position.
2. The multiplexer according to claim 1 , wherein the first frequency passband and the fourth frequency passband are the same.
3. The multiplexer according to claim 2 , wherein the second and third frequency passbands are offset from the first and fourth frequency passbands.
4. The multiplexer according to claim 2 , wherein the first and fourth frequency passbands are in a V-band frequency range of about 57 GHz to about 66 GHz.
5. The multiplexer according to claim 1 , wherein the second frequency passband is a first E-band frequency range of about 71 GHz to about 76 GHz and the third frequency passband is a second E-band frequency range of about 81 GHz to about 86 GHz.
6. The multiplexer according to claim 1 , wherein the second frequency passband is a first E-band frequency range of about 81 GHz to about 86 GHz and the third frequency passband is a second E-band frequency range of about 71 GHz to about 76 GHz.
7. The multiplexer according to claim 1 , wherein the second and third frequency passbands are offset from the first and fourth frequency passbands.
8. The multiplexer according to claim 1 , wherein the switch is a three-throw one-pole switch.
9. The multiplexer according to claim 1 , wherein the transmitter for the first frequency passband and the transmitter for the second frequency passband are provided by a single transmitter.
10. The multiplexer according to claim 1 , wherein the receiver for the third frequency passband and the receiver for the fourth frequency passband are provided by a single receiver.
11. The multiplexer according to claim 1 , wherein:
the first port of the first band filter and the first port of the second band pass filter form a common port of a first diplexer;
the second port of the second band pass filter and the second port of the third band pass filter form a common port of a second diplexer; and
the first port of the third band pass filter and the first port of the fourth band pass filter form a common port of a third diplexer.
12. A method comprising:
determining whether to operate in a time-division duplexing (TDD) mode or a frequency division duplexing (FDD) mode;
when the determination is to operate in the TDD mode:
during signal transmitting, coupling an antenna to a transmitter for a first frequency passband via a first band pass filter having the first frequency passband;
during signal receiving, coupling the antenna to a receiver for a fourth frequency passband via a fourth band pass filter having the fourth frequency passband; and
when the determination is to operate in the FDD mode, simultaneously coupling the antenna to a transmitter for a second frequency passband via a second band pass filter having the second frequency passband and to a receiver for a third frequency passband via a third band pass filter having the third frequency passband offset from the second frequency passband.
13. The method according to claim 12 , further comprising switching between signal transmitting and signal receiving in the TDD mode based on a predetermined TDD timing scheme.
14. The method according to claim 12 , wherein the first frequency passband and the fourth frequency passband are the same.
15. The method according to claim 14 , wherein the second and third frequency passbands are offset from the first and fourth frequency passbands.
16. The method according to claim 14 , wherein the first frequency passband and the fourth frequency passband are in a V-band frequency range of about 57 GHz to about 66 GHz.
17. The method according to claim 12 , wherein the second frequency passband is in a first E-band frequency range of about 71 GHz to about 76 GHz and the third frequency passband is in a second E-band frequency range of about 81 GHz to about 86 GHz.
18. The method according to claim 12 , wherein the second frequency passband is in a first E-band frequency range of about 81 GHz to about 86 GHz and the third frequency passband is in a second E-band frequency range of about 71 GHz to about 76 GHz.
19. The method according to claim 12 , wherein the second and third frequency passbands are offset from the first and fourth frequency passbands.
20. The method according to claim 12 , wherein the transmitter for the first frequency passband and the transmitter for the second frequency passband are provided by a single transmitter, and the receiver for the third frequency passband and the receiver for the fourth frequency are provided by a single receiver.