Spread spectrum communications using a reference and a message signal system and method

• US 7,099,292 B2
• Filed: 02/08/2002
• Issued: 08/29/2006
• Est. Priority Date: 12/05/1990
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Schilling, Donald L.
• Primary Examiner(s): HSU, ALPUS
• Application Number:
  US10/072,080
• Publication Number:
  US 20020126639A1
• Time in Patent Office: 1,663 Days
• Field of Search: 370/203, 370/206, 370/208, 370/329, 370/335, 370/342, 375/130, 375/140, 375/141, 375/145, 375/147, 375/149, 380/33, 380/34, 380/44, 380/46, 455/450, 455/451, 455/452, 455/456, 455/509, 455/517, 455/524, 455/67.1, 455/67.6
• US Class Current: 370/335
• CPC Class Codes: G01S 13/82 wherein continuous-type signals are transmitted
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/71 the interference being narrowband interference
• CPC Class Codes: H04B 1/7102 with transform to frequency domain
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04B 2201/709709 Methods of preventing interference
• CPC Class Codes: H04B 7/18547 for geolocalisation of a station position fixing by direction or distance determination G01S5/00
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]
• CPC Class Codes: H04B 7/2628 using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA] H04B7/2618 takes precedence
• CPC Class Codes: H04B 7/2631 for broadband transmission
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04W 4/12 Messaging; Mailboxes; Announcements
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 : Access point devices

Abstract

A spread spectrum remote unit produces a message signal having message data. A reference signal is produced. The reference signal is used to recover the message data from a combined spread spectrum signal. The reference signal and the message signal is combined as a combined signal. The combined signal is transmitted as the combined spread spectrum signal.

Claims

1. A spread spectrum communication system comprising:

means for producing a reference signal;

means for producing a message signal having message data;

means for combining the reference signal and the message signal as a combined signal;

means for transmitting the combined signal as a combined spread spectrum signal;

means for receiving the combined spread spectrum signal;

means, including a plurality of detector means, for detecting the reference signal within the received combined spread spectrum signal; and

means for recovering the message data using information from the detected reference signal by generating a local reference signal and synchronizing the local reference signal with the detected reference signal, said means for recovering demodulating each of a plurality of message data signals.

2. The system of claim 1 further comprising:

means for recovering a carrier signal from the combined spread spectrum signal using the local reference signal; and

wherein the message data recovering means uses the recovered carrier signal to recover the message data.

3. The system of claim 1 wherein the combined spread spectrum signal is in a code division multiple access format.

4. The system of claim 1 wherein a base station transmits the combined spread spectrum signal and a mobile station receives the combined spread spectrum signal.

5. The communication system of claim 1, wherein:

the means for generating the local reference signal relays the detected reference signal, the local reference signal transmitted as part of the combined spread spectrum signal; and

a second unit spread-spectrum processes message data with the local reference signal, and combines the spread-spectrum-processed message data with the local reference signal as a CDMA signal.

6. The communication system of claim 1, wherein:

the means for generating the local reference signal uses the detected reference signal to set the timing for the local reference signal, the local reference signal transmitted as part of the combined spread spectrum signal;

a second unit spread-spectrum processes the message data with the local reference signal, and combines the spread-spectrum-processed message data with the local reference signal as a CDMA signal; and

the second unit transmits said CDMA signal over a communications channel.

7. A method for use in a spread spectrum communication system, the method comprising:

producing a reference signal;

producing a message signal having message data;

combining the reference signal and the message signal as a combined signal;

transmitting the combined signal as a combined spread spectrum signal;

receiving the combined spread spectrum signal;

generating a local reference signal at a second unit;

synchronizing the local reference signal with a detected reference signal at the second unit;

using detector means and synchronization means to detect the reference signal within the received combined spread spectrum signal;

synchronizing the local reference signal with the detected reference signal; and

recovering the message data of the message signal using information from the detected reference signal, thereby demodulating the message signal.

8. The method of claim 7 further comprising:

recovering a carrier signal from the combined spread spectrum signal; and

wherein the step of recovering the message data uses the recovered carrier signal to recover the message data.

9. The method of claim 7 wherein the combined spread spectrum signal is in a code division multiple access format.

10. The method of claim 7 wherein a base station transmits the combined spread spectrum signal and a mobile station receives the combined spread spectrum signal.

11. The method of claim 7, further comprising:

using the generation of the local reference signal at the second unit to relay the detected reference signal, and transmitting the local reference signal from the second unit;

processing the local message data with the local reference signal, and combining the spread-spectrum-processed local message data with the local-reference signal as a local-CDMA signal; and

transmitting the local-CDMA signal over a communications channel.

12. The method of claim 7, further comprising:

generating the local reference signal at the second unit using the detected reference signal to set the timing for the local reference signal;

processing the local message data with the local reference signal, and combines the spread-spectrum-processed local message data with the local reference signal as a CDMA signal; and

transmitting the CDMA signal over a communications channel.

13. A spread spectrum communication system comprising:

means for producing a reference signal;

means for producing a message signal having message data;

means for combining the reference signal and the message signal as a combined signal;

means for transmitting the combined signal as a combined spread spectrum signal;

means for receiving a carrier signal of the combined signal using the reference signal; and

means for recovering the message data using information from the carrier signal, said means for recovering the message data including means for generating a local reference signal at a second unit and means to synchronize the local reference signal with the detected reference signal to produce a recovered carrier signal.

14. The system of claim 13 wherein the combined spread spectrum signal is in a code division multiple access format.

15. The system of claim 13 wherein a base station transmits the combined spread spectrum signal and a mobile station receives the combined spread spectrum signal.

16. The communication system of claim 13, wherein:

the means for generating the local reference signal at the second unit relays the detected reference signal, the local reference signal transmitted from the second unit;

the second unit spread-spectrum processes message data with the local reference signal, and combines the spread-spectrum-processed message data with the local reference signal as a CDMA signal; and

the second unit transmits said CDMA signal over a communications channel.

17. A method for use in a spread spectrum communication system, the method comprising:

producing a reference signal;

producing a message signal having message data;

combining the reference signal and the message signal as a combined signal;

transmitting the combined signal as a combined spread spectrum signal;

receiving the combined spread spectrum signal;

recovering a carrier signal of the combined spread spectrum signal using the reference signal by generating a local reference signal and synchronizing the local reference signal with the detected reference signal; and

recovering the message data using the recovered carrier signal, thereby demodulating the message signal.

18. The method of claim 17 wherein the combined spread spectrum signal is in a code division multiple access format.

19. The method of claim 17 wherein a base station transmits the combined spread spectrum signal and a mobile station receives the combined spread spectrum signal.

20. The method of claim 17, further comprising:

using the generation of the local reference signal to relay the detected reference signal, and transmitting the local reference signal;

processing the local message data with the local reference signal, and combining the spread-spectrum-processed local message data with the local-reference signal as a local-CDMA signal; and

transmitting the local-CDMA signal over a communications channel.