Power division multiple access

• US 9,596,679 B2
• Filed: 05/03/2016
• Issued: 03/14/2017
• Est. Priority Date: 08/30/2012
• Status: Active Grant

• Current Assignee: Gilat Satellite Networks Limited
• Original Assignee: Gilat Satellite Networks Limited
• Inventors: Elinav, Doron, Rubin, Mati E., Brener, Snir
• Primary Examiner(s): Morlan, Robert M
• Application Number:
  US15/145,142
• Publication Number:
  US 20160323856A1
• Time in Patent Office: 315 Days
• US Class Current: 1/1
• CPC Class Codes: H04B 7/18517 Transmission equipment in earth stations
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 5/22 using time-division multiplexing
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

A satellite communication system includes a hub and one or more terminals, wherein the one or more terminals may be configured to communicate over a satellite with the hub using a segment of the satellite'"'"'s resources and using a single channel per carrier (SCPC) access scheme. Methods are presented herein for facilitating the dimensioning of at least a power characteristic of said space segment using a Demand Assignment Multiple Access approach and for enforcing the dimensioned power characteristic in real-time, or substantially in real-time. Also presented are methods for allocating power to SCPC carriers, wherein a maximum power level for a carrier may be determined using a DAMA technique.

Claims

1. A terminal configured to:

receive, from a hub within a satellite communication system, allocation information corresponding to a channel for transmitting a carrier;

receive, from the hub, a maximum reception level at which the carrier is allowed to be received at the hub;

receive, from the hub, one or more reception level measurements corresponding to the carrier;

compare the maximum reception level at which the carrier is allowed to be received at the hub to at least one of the one or more reception level measurements corresponding to the carrier; and

regulate a power level at which the terminal transmits the carrier at least in accordance with the comparison and a data rate of data to be transmitted by the terminal.

2. The terminal of claim 1, wherein the terminal is further configured to:

reduce the power level at which the terminal transmits the carrier if the received one or more reception level measurements are higher than the maximum reception level corresponding to the carrier; and

change at least a modulation and coding combination (MODCOD) property of the carrier in accordance with at least one of a modified transmission power level or a change in received reception level measurements.

3. The terminal of claim 1, wherein the terminal is further configured to:

determine that a maximum reception level currently assigned to the carrier is too low for supporting a MODCOD needed for transmitting a target data rate; and

send a request, to the hub, for allocating a higher maximum reception level to the carrier.

4. The terminal of claim 1, wherein the terminal is further configured to:

determine the data rate for the data to be transmitted by the terminal;

determine a first modulation and coding combination (MODCOD) and a first maximum data rate corresponding to the first MODCOD, wherein the first MODCOD is a MODCOD used by the terminal at a time of a determination of the first MODCOD; and

determine that the determined data rate is greater than the first maximum data rate.

5. The terminal of claim 4, wherein the terminal is further configured to:

select a second MODCOD associated with a second maximum data rate, wherein the second maximum data rate is greater than the first maximum data rate; and

modify transmission power associated with the terminal, wherein modifying the transmission power comprises increasing the transmission power in accordance with at least a quasi-error-free (QEF) reception level associated with the second MODCOD.

6. The terminal of claim 5, wherein the terminal is further configured to:

receive one or more reception level indications from a receiver that receives the carrier; and

determine whether the carrier is received at a sufficient reception level in accordance with the one or more reception level indications and in accordance with the QEF reception level associated with the second MODCOD.

7. The terminal of claim 6, wherein the terminal is further configured to:

transmit the carrier using the second MODCOD if the carrier is received at a sufficient reception level in accordance with the QEF reception level associated with the second MODCOD.

8. The terminal of claim 7, wherein the terminal is further configured to:

determine that the determined data rate is less than the first maximum data rate;

select a third MODCOD associated with a third maximum data rate, wherein the third MODCOD is different from the first MODCOD and wherein the third maximum data rate is less than the first maximum data rate and greater than or equal to the determined data rate;

transmit the carrier using the third MODCOD;

modify the transmission power of the terminal, wherein modifying the transmission power comprises decreasing the transmission power in accordance with at least a QEF reception level associated with the third MODCOD; and

verify that the carrier is received at an appropriate reception level at least in accordance with the QEF reception level associated with the third MODCOD.

9. A satellite communication system, comprising the terminal of claim 1.

10. A method comprising:

receiving, by a terminal from a hub within a satellite communication system, allocation information corresponding to a channel for transmitting a carrier;

receiving, by the terminal from the hub, a maximum reception level at which the carrier is allowed to be received at the hub;

receiving, by the terminal from the hub, one or more reception level measurements corresponding to the carrier;

comparing, by the terminal, the maximum reception level at which the carrier is allowed to be received at the hub to at least one of the one or more reception level measurements corresponding to the carrier; and

regulating, by the terminal, a power level at which the terminal transmits the carrier at least in accordance with the comparison and a data rate of data to be transmitted by the terminal.

11. The method of claim 10, wherein the regulating comprises reducing the power level at which the terminal transmits the carrier if the received one or more reception level measurements are higher than the maximum reception level corresponding to the carrier, the method further comprising:

changing at least a modulation and coding combination (MODCOD) property of the carrier in accordance with at least one of a modified transmission power level or a change in received reception level measurements.

12. The method of claim 10, further comprising:

determining that a maximum reception level currently assigned to the carrier is too low for supporting a MODCOD needed for transmitting a target data rate; and

sending a request, from the terminal to the hub, for allocating a higher maximum reception level to the carrier.

13. The method of claim 10, further comprising:

determining the data rate for the data to be transmitted by the terminal;

determining a first modulation and coding combination (MODCOD) and a first maximum data rate corresponding to the first MODCOD, wherein the first MODCOD is a MODCOD used by the terminal at a time of the determining of the first MODCOD; and

determining that the determined data rate is greater than the first maximum data rate.

14. The method of claim 13, further comprising:

selecting a second MODCOD associated with a second maximum data rate, wherein the second maximum data rate is greater than the first maximum data rate; and

modifying transmission power associated with the terminal, wherein the modifying comprises increasing the transmission power in accordance with at least a quasi-error-free (QEF) reception level associated with the second MODCOD.

15. The method of claim 14, further comprising:

receiving one or more reception level indications from a receiver that receives the carrier; and

determining whether the carrier is received at a sufficient reception level in accordance with the one or more reception level indications and in accordance with the QEF reception level associated with the second MODCOD.

16. The method of claim 15, further comprising:

transmitting the carrier using the second MODCOD if the carrier is received at a sufficient reception level in accordance with the QEF reception level associated with the second MODCOD.

17. The method of claim 16, further comprising:

determining that the determined data rate is less than the first maximum data rate;

selecting a third MODCOD associated with a third maximum data rate, wherein the third MODCOD is different from the first MODCOD and wherein the third maximum data rate is less than the first maximum data rate and greater than or equal to the determined data rate;

transmitting the carrier using the third MODCOD;

modifying the transmission power of the terminal, wherein the modifying comprises decreasing the transmission power in accordance with at least a QEF reception level associated with the third MODCOD; and

verifying that the carrier is received at an appropriate reception level at least in accordance with the QEF reception level associated with the third MODCOD.

18. A method comprising:

determining, by a terminal of a satellite communication system, a data rate for data to be transmitted;

in response to the determining the data rate, determining a first modulation and coding combination (MODCOD) for transmitting a carrier and determining a first maximum data rate for transmitting the data over the carrier using the first MODCOD;

comparing the data rate with the first maximum data rate;

in response to determining that the data rate is greater than the first maximum data rate, selecting a second MODCOD that supports a second maximum data rate for transmitting the data over the carrier; and

in response to selecting the second MODCOD;

increasing a transmission power of the terminal in accordance with at least a quasi-error-free (QEF) normalized symbol energy over noise (E_S/N₀) level associated with the second MODCOD;

receiving a reception level indication; and

determining whether the indicated reception level satisfies a threshold E_S/N₀ level associated with the second MODCOD.

19. The method of claim 18, wherein the receiving the reception level indication comprises receiving the reception level indication from a hub of the satellite communication system.

20. The method of claim 18, further comprising:

in response to determining that the indicated reception level does not satisfy a threshold E_S/N₀ level associated with the second MODCOD, determining whether additional transmission power is available;

in response to determining that additional transmission power is available, further increasing the transmission power of the terminal;

in response to the further increasing the transmission power of the terminal, selecting an intermediate MODCOD in accordance with the reception level indication, wherein the intermediate MODCOD is different from both the first MODCOD and the second MODCOD and wherein the intermediate MODCOD is associated with a QEF E_S/N₀ level that is higher than a QEF E_S/N₀ level associated with the first MODCOD but lower than or equal to the QEF E_S/N₀ level associated with the second MODCOD; and

transmitting the carrier in accordance with the intermediate MODCOD before the transmission power, for supporting the second MODCOD, is stabilized.