Method and apparatus for selectively-enabled diversity signaling in a radio communications system

• US 5,345,600 A
• Filed: 08/31/1993
• Issued: 09/06/1994
• Est. Priority Date: 08/31/1993
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Davidson, Allen L.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): LIN, MARY
• Application Number:
  US08/114,526
• Time in Patent Office: 371 Days
• Field of Search: 455/8, 455/9, 455/10, 455/52.3, 455/65, 455/101, 455/54.1, 455/50.1, 370/95.1, 370/95.3, 370/69.1, 375/38
• US Class Current: 455/501
• CPC Class Codes: H04B 7/02 Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas RAKE receivers H04B1/7115
• CPC Class Codes: H04B 7/12 Frequency diversity
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/04 using frequency diversity

Abstract

In a radio communications system, a selectively enabled time- and/or frequency-diverse signaling scheme is employed to improve signal quality. In particular, a method of exchanging a message between communication devices using a communications resource might include the step of transmitting a first portion of the message on a first frequency within the communications resource. After determining the quality of the communications resource to be unfavorable, a second portion of the message might be transmitted on the first frequency, and also re-transmitted on a second frequency and/or at a separate time.

Claims

1. In a radio communications system, a method for exchanging a message between a plurality of communication devices using a communications resource, the method comprising the steps of:

A) transmitting, from a first of the plurality of communication devices a first portion of the message on a first frequency within the communications resource;

B) determining the quality of the communications resource; and

C) when the quality of the communications resource is unfavorable, transmitting a second portion of the message on the first frequency and on a second frequency.

2. The method of claim 1, wherein step B) comprises the step of:

at the first communication device;

B1) calculating a signal quality metric for a signal sent from a second communication device; and

B2) transmitting the signal quality metric to the second communication device.

3. The method of claim 1, further comprising the step of:

D) identifying a time when the signal-to-noise ratio (SNR) of the first portion of the message falls below a predetermined threshold as being when the quality of the communications resource is unfavorable.

4. The method of claim 1, further comprising the step of:

D) identifying a time when the bit error rate (BER) for the first portion of the message falls below a predetermined threshold as being when the quality of the communications resource is unfavorable.

5. The method of claim 1, further comprising the step of:

D) transmitting, in response to the step of determining, the second portion of the message on a third frequency.

6. In a radio communications system, a method for exchanging a message between a plurality of communication devices using a communications resource, the method comprising the steps of:

A) transmitting, from a first of the plurality of communication devices, a first portion of the message at a first time on a first frequency within the communications resource;

B) determining the quality of the communications resource; and

C) when the quality of the communications resource is unfavorable, transmitting a second portion of the message at a time corresponding to the first time on the first frequency and at a second time on the first frequency.

7. The method of claim 6, wherein step B) comprises the step of:

at the first communication device;

B1) calculating a signal quality metric for a signal sent from a second communication device; and

B2) transmitting the signal quality metric to the second communication device.

8. The method of claim 6, further comprising the step of:

D) identifying a time when the signal-to-noise ratio (SNR) of the first portion of the message falls below a predetermined threshold as being when the quality of the communications resource is unfavorable.

9. The method of claim 6, further comprising the step of:

D) identifying a time when the bit error rate (BER) for the first portion of the message falls below a predetermined threshold as being when the quality of the communications resource is unfavorable.

10. The method of claim 6, further comprising the step of:

D) transmitting, in response to the step of determining, the second portion of the message at a third time on the first frequency.

11. The method of claim 6, wherein the communications resource includes a plurality of time division multiple access (TDMA) frames on the first frequency, and step A) comprises the step of transmitting the second portion of the message in a first timeslot within a first of the plurality of TDMA frames.

12. In a radio communications system, a method for exchanging a message between a plurality of communication devices using a communications resource, the method comprising the steps of:

A) transmitting, from a first of the plurality of communication devices, a first portion of the message at a first time on a first frequency within the communications resource;

B) determining the quality of the communications resource; and

C) when the quality of the communications resource is unfavorable, transmitting a second portion of the message at a time associated with the first time on the first frequency and at a second time on a second frequency within the communications resource.

13. The method of claim 12, wherein step B) comprises the step of:

at the first communication device;

B1) calculating a signal quality metric for a signal sent from a second communication device; and

B2) transmitting the signal quality metric to the second communication device.

14. The method of claim 12, further comprising the step of:

D) identifying a time when the signal-to-noise ratio (SNR) of the first portion of the message falls below a predetermined threshold as being when the quality of the communications resource is unfavorable.

15. The method of claim 12, further comprising the step of:

D) identifying a time when the bit error rate (BER) for the first portion of the message falls below a predetermined threshold as being when the quality of the communications resource is unfavorable.

16. The method of claim 12 wherein the communications resource includes a plurality of time division multiple access (TDMA) frames on the first frequency and a plurality of TDMA frames on the second frequency, and step A) comprises the step of:

A1) transmitting the first portion of the message in a first timeslot within a first of the plurality of TDMA frames on the first frequency; and

wherein step C) comprises the step of;

C1) transmitting the second portion of the message in the first timeslot and in a second timeslot within a second of the plurality of TDMA frames on the second frequency.

17. A data transmitter for transmitting a message to a communication device using a communications resource, the communications resource including a plurality of time division multiple access (TDMA) frames on a first frequency and a plurality of TDMA frames on a second frequency, the data transmitter comprising:

means for transmitting a first portion of the message in a first timeslot within a first of the plurality of TDMA frames on the first frequency;

means for determining the quality of the first timeslot; and

means, operably coupled to the means for determining, for transmitting a second portion of the message in the first timeslot and in a second timeslot within a second of the plurality of TDMA frames on the second frequency.