Method for real time control of transmit chain for software radios

• US 20040037282A1
• Filed: 08/22/2002
• Published: 02/26/2004
• Est. Priority Date: 08/22/2002
• Status: Active Grant

• Current Assignee: Callahan Cellular LLC (Intellectual Ventures LLC)
• Original Assignee: BAE Systems Information and Electronic Systems Integration Incorporated (BAE Systems Plc)
• Inventors: Luthi, Peter O., Boland, Robert P., Thiele, Matthew J., Simonson, Peter
• Granted Patent: US 7,573,863 B2
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling

Abstract

In a communications or jamming system, accurate timing for the control of the frequency, amplitude, modulation type, pulse repetition rate or other transmit characteristics is achieved for the transmission of digitally processed packetized signals through the use of standard non-realtime off-the-shelf components for the digital processing and a realtime interface which reads transmit chain headers and, with the assistance of a precise time reference, assures that the transmit chain is configured in time to transmit the packets. Note that the realtime interface assures nanosecond timing accuracy regardless of timing errors introduced by the off-the-shelf components used in upstream digital processing.

Claims

1. A method for the precision control of a transmit chain in the transmission of packetized data such that the transmit chain is configured to transmit a packet in realtime, comprising the steps of:

generating packets of data in non-realtime, having a header including a time stamp indicating when a packet is to be sent and a header describing the characteristics that the transmit chain is to have when transmitting a packet; and

,

configuring the transmit chain in realtime responsive to the header describing the characteristics that the transmit chain is to have, whereby non-realtime processing can be accomplished by off-the-shelf components having non-realtime accuracies, the accuracy of the timing for configuring the transmit chain being sufficient to configure the transmit chain in time to transmit the packet at a designated precise time.

2. The method of claim 1, wherein a packet is transmitted at the precise time corresponding to the associated time stamp thereof, and wherein the configuring step includes configuring the transmit chain sufficiently prior to the precise time that the packet is to be transmitted to permit transmission of the packet at the precise time therefore, thus to permit precision on the fly reconfiguring of the transmit chain.

3. The method of claim 1, wherein the transmit chain characteristics are taken from the group consisting of frequency, amplitude and modulation type.

4. A method for the realtime control of a transmit chain for the transmission of packetized data, comprising the steps of:

generating the packets of data with off-the-shelf components having non-realtime accuracies; and

,

providing realtime control signals for configuring the transmit chain without using non-realtime components, whereby on the fly changes in the transmit chain can be realized without the necessity of providing all realtime components, thus to minimize the cost of controlling the transmit chain.

5. The method of claim 4, wherein the packets are provided with headers specifying the transmit chain characteristic for the transmission of a packet, and wherein the realtime control signals are generated responsive to the header specifying the transmit chain characteristic for a packet.

6. The method of claim 5, wherein the packets are buffered prior to transmission and wherein the buffered headers are read at a precise time in relation to the time at which the packet is to be transmitted by the transmit chain.

7. The method of claim 6, wherein the precise time is established by a realtime clock.

8. The method of claim 7, wherein the realtime clock has nanosecond accuracy.

9. The method of claim 7, wherein the realtime clock includes a GPS receiver for referencing the realtime clock to Greenwich Mean Time.