Method and apparatus for multiple accesses to a communications channel

• US 20110076953A1
• Filed: 09/25/2009
• Published: 03/31/2011
• Est. Priority Date: 09/25/2009
• Status: Active Grant

• Current Assignee: Nigel Iain Stuart Macrae
• Original Assignee: Nigel Iain Stuart Macrae
• Inventors: Macrae, Nigel Iain Stuart
• Granted Patent: US 8,351,404 B2
• Time in Patent Office: Days
• US Class Current: 455/59
• CPC Class Codes: G06F 11/1443 Transmit or communication errors
• CPC Class Codes: H04B 7/0671 using different delays between antennas
• CPC Class Codes: H04B 7/084 Equal gain combining, only phase adjustments antenna beam scanning or forming by phase or amplitude control H01Q3/26, e.g. phased arrays
• CPC Class Codes: H04B 7/12 Frequency diversity
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements

Abstract

A method and apparatus for increasing user capacity in a multi-user communication system. The method comprises transmitting a signal multiple times in the communication system with a predetermined delay between each retransmission. A receiver receives the signals and makes multiple delayed copies of the signal which are then summed. A second signal is then transmitted multiple times in the communication system with a different delay time between each retransmission than the first signal, and then received by a receiver which makes multiple delayed copies of this second signal which are then summed and decoded. This process is then used on subsequent signals in the communication system.

Claims

1. A method for multiple transmitter access to an electromagnetic communication system, comprising:

transmitting a first signal repeated multiple times on a frequency in said communication system, said signal being transmitted with a determined set of delays between each retransmission;

receiving said signal by receiving means, said receiving means making multiple delayed copies of said signal using said determined set of delays;

transmitting a second signal multiple times on said same frequency in said communication system, said second signal being transmitted with a different set of delays than the first signal; and

receiving said second signal, by said receiving means, said receiving means making multiple delayed copies of said second signal, then delaying said copies using the delay set for the second signal, and then combining said delayed copies.

2. The method of claim 1, wherein a plurality of signals are transmitted multiple times over a frequency in said communication system, each of said plurality of signals having a delay time between each transmission different from any other retransmitted signal.

3. The method of claim 1, wherein said first signal is transmitted multiple times in said communication system;

subsequently, these multiple signals are received, copied, then delayed using the reverse delays of the known delay set, then summed together at said receiving means.

4. The method of claim 1, wherein said second signal is transmitted multiple times in said communication system, and said second signal is received by receiving means wherein said second signal is split into multiple copies, said copies are then delayed using the reverse of the known delay set, and then combined together.

5. The method of claim 1, wherein said plurality of signals which are transmitted multiple times in said communication system and are each summed at said receiving means.

6. The method of claim 1, wherein any two different data signals are transmitted using a delay set that is unique to each data signal and do not have timing intervals between retransmissions that are identical between two delay sets.

7. The method of claim 1 wherein the multiple delayed copies of the data signal are combined at an intermediate frequency before transmission and then upconverted to the final transmission frequency;

then at the receive end the received signal is down converted to an intermediate signal then copied and delayed using the known delay set, then the copies are combined.

8. The method of claim 1, wherein said delayed copies of said signal are also transmitted on different frequencies in said communication system.

9. The method of claim 1, wherein if an error detection means in said receiving means detects a high level of errors in transmission of said signal, more copies of said signal are transmitted to said receiving means.

10. The method of claim 1, wherein if an error detection means in said receiving means detects a high level of errors in transmission of said signal, the data rate of the transmitted signal is reduced.

11. The method of claim 1, wherein if an error detection means in said receiving means detects a high level of errors in transmission of said signal, the power at which the signal and its copies are transmitted is increased

12. The method of claim 1 used in a satellite communications network.

13. The method of claim 1 wherein the signal is transmitted in a burst mode, wherein each copy of the signal has a finite duration, wherein each copy is delayed before transmission until the burst transmission of the previous copy is completed.

14. The method of claim 13 where upon reception each burst is delayed until they are all time aligned, and then summed.

15. The method of claim 1 wherein both the transmitter and the receiver use a mutually known delay set.

16. The method of claim 1 wherein the delay set is communicated from the transmit station to the receive station.

17. The method of claim 1 wherein the delay set is communicated from the receive station to the transmit station.

18. A method for increasing user capacity in a communication system, comprising:

transmitting a signal multiple times on a frequency in said communication system, said signal being transmitted with a predetermined delay between each retransmission; and

receiving said signal by receiving means, said receiving means making multiple delayed copies of said signal, and summing said multiple delayed copies of the signal.

19. The method of claim 18, wherein any two different signals transmitted in said communication system use different delay sets of times in-between retransmission.

20. The method of claim 18, when an error detection means in said receiving means detects a high level of errors in transmission of said signals, more copies of said signal are transmitted to said receiving means.

21. An apparatus for increasing user capacity in a communication system, comprising:

means for transmitting a signal multiple times on a frequency in said communication system, said signal being transmitted with a predetermined delay between each retransmission; and

receiving means for receiving said signal, said receiving means making multiple delayed copies of said signal;

for combining, demodulation, and decoding.

22. The apparatus of claim 21, wherein said transmitting means transmits a plurality of signals multiple times over a frequency in said communication system, each of said plurality of signals having a different predetermined delay time, and said receiving means receives, makes multiple copies, delays each copy by the reverse predetermined delay, and sums the copies for each of said plurality of signals transmitted in the communication system.