RF amplification system and method

• US 20060217061A1
• Filed: 02/28/2006
• Published: 09/28/2006
• Est. Priority Date: 03/01/2005
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Audiological Engineering Corporation
• Inventors: Steele, Michael, Franklin, David
• Granted Patent: US 7,672,637 B2
• Time in Patent Office: Days
• US Class Current: 455/3.60
• CPC Class Codes: H04H 60/92 for local area
• CPC Class Codes: H04R 27/00 Public address systems circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; monitoring or testing arrangements for public address systems H04R29/007; amplifiers H03F

Abstract

Spread-spectrum technology, either direct sequence or frequency hopping, or a combination of the two, is used for transmitting audio signals one way and control signals two ways over an RF channel(s) to reduce interference with/from other RF transmissions and enabling use of multiple such systems in close proximity without requiring pre-selection of transmission frequencies. Alternatively, multiple channels with appended access codes may be used, wherein interference or loss of clear signal results in automatic switching to another channel. The control signals accompany the transmitted audio signal at some time in the transmission interval, or previous to the beginning of the transmission interval, and constitute a coded control message allowing a unique connection. In some cases the encoding keys may only occur at the beginning of the desired message, while in other cases the two-way control signals may continue throughout the interval of the message link.

Claims

1. A method for delivering amplified audio signals into a venue comprising the steps of:

at a first location;

(a) generating an audio signal;

(b) generating a first control signal;

(c) generating a first RF signal;

(d) encoding said first RF signal with said audio signal and said first control signal;

(e) from a first transmitter, wirelessly transmitting in spread spectrum format said first RF signal encoded with said audio signal and said first control signal;

(f) at a first receiver wirelessly receiving in spread spectrum format a second RF signal containing a second control signal but no audio signal;

(g) detecting said second RF signal and separating therefrom said second control signal;

(h) Identifying the separated second control signal;

(i) evaluating the separated second control signal for controlling transmission of said first RF signal in accordance with values of the second control signal;

at a second location spaced from said first location;

(j) at a second receiver, wirelessly receiving the transmitted first RF signal in spread spectrum format containing said audio signal and said first control signal;

(k) detecting said first RF signal and separating said audio signal and said first control signal therefrom;

(l) identifying the separated first control signal;

(m) evaluating the separated first control signal and controlling delivery of the separated audio signal in accordance with values of the first control signal;

(n) rendering the separated audio signal audible if and only if said first control signal contains predetermined instructions to do so;

(o) generating the second control signal;

(p) generating the second RF signal;

(q) encoding said second RF signal with said second control signal; and

(r) from a second transmitter, wirelessly transmitting in spread spectrum format said second RF carrier signal containing said second control signal but no audio signal;

thereby effecting one-way spread spectrum transmission of audio signals and two-way spread spectrum transmission of control signals between said first and second locations.

2. The method of claim 1 wherein said spread spectrum format is either direct sequence or frequency hopping.

3. The method of claim 1 wherein a one-way point-to-point audio link is established using two-way control signaling, and wherein said control signals may either be continuous throughout the time after such a point-to-point audio link is established, or may cease as long as the audio link is maintained.

4. The method of claim 1 wherein both said first and second transmitters are programmed to provide said first and second control signals, respectively, and said first and second receivers are programmed to recognize said second and first control signals, respectively, such that the first and second receivers uniquely accept data from the second and first transmitters, respectively, and reject data from un-programmed and improperly programmed transmitters.

5. The method of claim 1 wherein different RF bands are utilized for transmission of audio signals and control signals.

6. The method of claim 1 wherein the one-way transmission of audio signals and two-way transmission of control signals is via plural synchronous channels in a manner as to obtain increased bandwidth.

7. The method of claim 1 wherein the first control signal includes:

a frequency identity code which identifies an RF carrier frequency via which said first control signal is transmitted; and

a code uniquely identifying said first transmitter as the source of said audio signal.

8. A system for delivering amplified audio signals into a venue comprising:

at a first location;

an audio signal source or generating an audio signal;

first control signal means for generating a first control signal;

RF signal means for generating a first RF signal;

first encoder means for encoding said first RF signal with said audio signal and said first control signal;

a first transmitter for wirelessly transmitting said first RF signal encoded with said audio signal and said first control signal;

a first receiver for wirelessly receiving a second RF signal containing a second control signal but no audio signal;

a first detector for detecting said second RF signal and separating therefrom said second control signal;

first decoder means for Identifying the separated second control signal and evaluating the separated second control signal for controlling transmission of said first RF signal by said first transmitter in accordance with values of the second control signal;

at a second location spaced from said first location;

a second receiver for for wirelessly receiving the transmitted first RF signal containing said audio signal and said first control signal;

a second detector for detecting said first RF signal and separating said audio signal and said first control signal therefrom;

second decoder means for identifying the separated first control signal and evaluating the separated first control signal for controlling delivery of the separated audio signal in accordance with values of the first control signal;

means for rendering the separated audio signal audible if and only if said first control signal contains predetermined instructions to do so;

second control signal means for generating the second control signal;

RF signal means for generating the second RF signal;

second encoder means for encoding said second RF signal with said second control signal; and

a second transmitter for wirelessly transmitting said second RF carrier signal containing said second control signal but no audio signal;

thereby effecting one-way transmission of audio signals and two-way transmission of control signals between said first and second locations.

9. The system of claim 8 wherein said first and second transmitters transmit said first and second RF signals, respectively, in spread spectrum format.

10. The system of claim 9 wherein said spread spectrum format is either direct sequence or frequency hopping.

11. The system of claim 8 wherein a one-way point-to-point audio link is established using two-way control signaling, and wherein said first and second transmitters include means for transmitting said first and second control signals, respectively, continuously throughout the time after such a point-to-point audio link is established.

12. The system of claim 8 wherein both said first and second transmitters include program means to provide said first and second control signals, respectively, and said first and second receivers include means to recognize said second and first control signals, respectively, such that the first and second receivers uniquely accept data from the second and first transmitters, respectively, and reject data from un-programmed and improperly programmed transmitters.

13. The system of claim 8 wherein sad first and second transmitters each include means for changing transmission of said RF signals to different RF frequency bands.

14. The system of claim 8 wherein the one-way transmission of audio signals and two-way transmission of control signals is via plural synchronous channels in a manner as to obtain increased bandwidth.

15. The system of claim 8 wherein the first control signal includes:

a frequency identity code to identify an RF carrier frequency via which said first control signal is transmitted; and

a code uniquely identifying said first transmitter as the source of said audio signal.

16. The system of claim 8 wherein said first and second encoder means are digital encoders.

17. A method for implementing sound transmissions comprising establishing at least one point-to-point asynchronous data channel to obtain substantially real time one-way sound transmissions with accompanying two-way transmission of control signals and wider sound bandwidths.

18. The method of claim 17 wherein transmission of said two-way control signals is continuous for as long as said data channel is established.

19. The method of claim 17 wherein transmission of said two-way control signals occurs only initially to establish said data channel.