Method to increase the bit rate in a communications system

• US 20070014387A1
• Filed: 08/21/2006
• Published: 01/18/2007
• Est. Priority Date: 08/10/2001
• Status: Active Grant

• Current Assignee: Thales SA
• Original Assignee: Thales SA
• Inventors: Morgand, Philippe, Chenu-Tournier, Marc
• Granted Patent: US 7,664,195 B2
• Time in Patent Office: Days
• US Class Current: 375/347
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04B 7/0851 using training sequences or error signal minimizing error signal H04B7/0854
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion

Abstract

Disclosed is a method and a device to increase the bit rate in a communications system comprising N transmitters (2_N) and M receivers (3_M), with M greater than or equal to N. The method comprises the following steps.

• • a) simultaneously sending different messages on several of the N (2_N) transmitters,
  • b) simultaneously receiving the superimposition of the messages sent during the step a) on several of the M (3_M) receivers or reception sensors, c) estimating the characteristics of the transmission channel for each pair constituted by a transmission sensor and a receiver sensor, d) jointly estimating all or at least the majority of the messages received in taking account of the signals as well as the characteristics of the transmission channel. Application to GSM signals and to systems of unicast transmission and multicast transmission, namely multipoint-to-point and multipoint-to-multipoint transmission.

Claims

1. A receiver apparatus in a communication system including N transmitters and M receivers, with M greater than or equal to N, said receiver being one of said M receivers, said receiver comprising:

a reception agent configured to simultaneously receive a superimposition of different messages sent by the N transmitters; and

a demodulating agent configured to decode a signal received by the reception agent;

a channel estimating agent configured to estimate a characteristic of a transmission channel between one of said N transmitters and said receiver, and configured to jointly estimate a characteristic of the transmission channel by using information of all of the different message.

2. A receiver apparatus according to claim 1, further comprising:

an equalizer filter configured to minimize a mean squared error between an output of said equalizer filter and a corresponding real symbol, said equalizer filter having a feed forward filtering function and a feed back filtering function.

3. The receiver apparatus according to claim 1, wherein the reception agent is further configured to receive messages sent using MIMO unicast transmission.

4. The receiver apparatus according to claim 1, wherein the reception agent is further configured to receive messages sent using MIMO multicast transmission.

5. The receiver apparatus according to claim 1, wherein the demodulating agent comprises a SGWN (Standard Gaussian White Noise) demodulator.

6. The receiver apparatus according to claim 5, wherein the SGWN demodulator is implemented by a Viterbi decoder.

7. The receiver apparatus according to claim 2, wherein the equalizer filter further comprises a MF (Matched Filter).

8. The receiver apparatus according to claim 2, wherein the equalizer filter further comprises a DFE ZF (Decision Feedback Equalizer-Zero Forcing Filter).

9. The receiver apparatus according to claim 2, wherein the equalizer filter further comprises a DFE MMSE (Decision Feedback Equalizer-Minimum Mean Squared Error Filter).

10. A receiver apparatus in a communication system including N transmitters and M receivers, with M greater than or equal to N, said receiver being one of said M receivers, said receiver comprising:

means for receiving simultaneously a superimposition of different messages sent by the N transmitters;

means for demodulating to decode a received signal; and

means for estimating a characteristic of a transmission channel between one of said N transmitters and said receiver; and

for estimating a characteristic of the transmission channel by using information of all of the different messages.

11. The receiver apparatus according to claim 10, further comprising:

means for equalizing to minimize a mean squared error between an output of said equalizing means and a corresponding real symbol, said equalizing means having a feed forward filtering function and a feed back filtering function.

12. A receiving method configured to operate in a communication system including N transmitters and M receivers, with M greater than or equal to N, said receiver being one of said M receivers, said receiving method comprising:

receiving simultaneously a superimposition of different messages sent by the N transmitters;

demodulating to decode a received signal;

estimating a characteristic of a transmission channel between one of said N transmitters and said receiver; and

estimating a characteristic of the transmission channel by using information of all of the different messages.

13. The method of claim 12, further comprising:

minimizing a mean squared error between an output of an equalizing means and a corresponding real symbol, said minimizing including filtering with a feed forward filtering function and a feed back filtering function.

14. The method of claim 12, further comprising:

receiving messages sent using MIMO unicast transmission.

15. The method of claim 12, further comprising:

receiving messages sent using MIMO multicast transmission.

16. The method of claim 12, further comprising:

estimating the characteristics of the transmission channel using a training sequence included in a message.

17. The method of claim 12, further comprising:

demodulating the received signal with a SGWN (Standard Gaussian Wide Noise) demodulator.

18. The method of claim 12, wherein the SGWN demodulator is a Viterbi decoder.

19. The method of claim 12, further comprising:

equalizing using a MF (Matched Filter).

20. The method of claim 12, further comprising:

equalizing using a DFE ZFF (Decision Feedback Equalizer-Zero Forcing Filter).

21. The method of claim 12, further comprising:

equalizing using a DFE MMSE (Decision Feedback Equalizer-Minimum Mean Squared Error Filter).