Method and apparatus for transmitting communication signals using frequency and polarization diversity

• US 6,243,565 B1
• Filed: 01/31/1997
• Issued: 06/05/2001
• Est. Priority Date: 06/18/1996
• Status: Expired due to Fees

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Smith, David Anthony, Olofsson, Håkan Gunnar, Almgren, Knut Magnus
• Primary Examiner(s): Urban, Edward F.
• Application Number:
  US08/791,195
• Time in Patent Office: 1,586 Days
• Field of Search: 455/101, 455/102, 455/103, 455/560, 455/561, 455/562, 375/299, 342/361
• US Class Current: 455/101
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 7/0604 with predefined switching scheme
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04B 7/12 Frequency diversity
• CPC Class Codes: H04L 1/06 using space diversity

Abstract

A transmitter diversity assembly and an associated method for a radio transmitter. When coupled to a radio transmitter to form a portion thereof, signal diversity is created to overcome multi-path fading. A plurality of antennas are freely selectable to be coupled to receive bursts of a communication signal, modulated to be transmitted on any of selected carriers. By altering the carriers upon which the bursts of the communication signal are transmitted and the spatially-separated antennas used to transduce the bursts of the communication signal, both transmission space diversity and frequency diversity is created. Polarization diversity is further provided by utilization of dual-polarized antennas.

Claims

1. A transmitter diversity assembly for a communication station having a tunable transmitter operable to generate a communication signal of a plurality of frequencies, said transmitter diversity assembly comprising:

at least one dual-polarized antenna selectively connectable to receive the communication signal generated at the communication station, said at least one dual-polarized antenna for transducing the communication signal when applied thereto according to a selected polarization;

a polarization selector coupled to the communication station, said polarization selector for selecting the polarization of said at least one dual-polarized antenna, the polarizations selected by said polarization selector selected to form a sequence of at least an alternating polarization; and

a transmitter controller coupled to the communication station, said transmitter controller for causing the tunable transmitter to operate at a selected one of the plurality of frequencies and for causing the polarization selector to select one of the polarizations forming the sequence of the at least an alternating polarization;

wherein the communication signal transduced by said at least one dual-polarized antenna has both frequency diversity and polarization diversity.

2. The transmitter diversity assembly of claim 1 wherein said at least one dual-polarized antenna comprises a first dipole antenna and a second dipole antenna, the first dipole antenna for forming a first polarization and the second dipole antenna for forming a second polarization.

3. The transmitter diversity antenna assembly of claim 1 wherein said at least one dual-polarized antenna comprises a micro-strip antenna capable of forming a first polarization and a second polarization.

4. The transmitter diversity antenna of claim 1 wherein said at least one dual-polarized antenna comprises a single, dual-polarized antenna capable of forming at least alternately a first polarization and a second polarization.

5. The transmitter diversity antenna of claim 1 wherein said at least one dual-polarized antenna comprises a first dual-polarized antenna and a second dual-polarized antenna, said first and second dual-polarized antennas, respectively, together capable of forming a first polarization, a second polarization, a third polarization, and a fourth polarization.

6. The transmitter diversity assembly of claim 5 wherein said polarization selector further comprises a switch, said switch for at least alternately coupling said first dual-polarized antenna and said second dual-polarized antenna to receive the communication signal.

7. The transmitter diversity assembly of claim 1 wherein the communication signal is transmitted upon a plurality of communication channels, wherein the tunable transmitter generates a communication signal at a carrier frequency corresponding to a selected communication channel of the plurality of communication channels and wherein said at least one dual-polarized antenna transduces the communication signal to be transmitted upon the selected communication channel corresponding to the carrier frequency at which the transmitter generates the communication signal.

8. The transmitter diversity assembly of claim 1 wherein the selected polarizations selected by said polarization selector are selected responsive to a fading characteristic exhibited upon at least one communication channel that corresponds to a frequency and polarization combination of a selected sequence of frequency and polarization pattern combinations.

9. A method for transmitting a communication signal generated by a transmitter of a communication station upon at least one communication channel to a remote station, said method comprising the steps of:

selectively connecting at least on dual-polarized antenna to receive the communication signal;

selecting a polarization to be exhibited by the at least one dual-polarized antenna;

transducing the communication signal at the at least one dual-polarized antenna connected during said step of selectively connecting, thereby to transmit the communication signal to the remote station; and

selecting a carrier frequency to be exhibited by the communication signal during said step of transducing;

whereby the communication signal transduced has both frequency diversity and polarization diversity.

10. The method of claim 9 further comprising the step of providing the communication station with indications of a transmission characteristic of the at least one communication channel;

and

wherein the at least one communication channel of which the indications of the transmission characteristic are provided during said step of providing comprises a downlink channel upon which communication signals are transmitted by the communication station to the remote station.

11. The method of claim 9 wherein the at least one dual-polarized antenna selectively connected during said step of selectively connecting comprises a first dipole antenna and a second dipole antenna.

12. The method of claim 9 wherein the at least one dual-polarized antenna selectively connected during said step of selectively connecting comprises a transmission line capable of exhibiting a first polarization and a second polarization.

13. The method of claim 9 wherein the polarization selected during said step of selecting is alternately a first polarization and a second polarization.

14. The method of claim 9 wherein the at least one dual-polarized antenna selectively connected during said step of selectively connecting comprises a first dual-polarized antenna and a second dual-polarized antenna spaced-apart therefrom, and wherein the polarization selected during said step of selecting is selectively a first polarization, a second polarization, a third polarization, and a fourth polarization.