Method and apparatus for transmitting data

• US 6,373,884 B1
• Filed: 03/11/1997
• Issued: 04/16/2002
• Est. Priority Date: 03/11/1997
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Byrns, John Paul
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Tran, Congvan
• Application Number:
  US08/814,395
• Time in Patent Office: 1,862 Days
• Field of Search: 375/219, 375/220, 375/228, 375/230, 375/368, 375/363, 370/474, 370/465, 370/522, 370/410, 370/384, 370/377, 370/373, 370/349, 380/15, 380/20, 380/42, 380/44, 380/48
• US Class Current: 375/219
• CPC Class Codes: H04L 25/49 using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems spectral shaping H04L25/03828
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A method and apparatus for transmitting data improves efficiency and guarantees consistency in the data transmission rate. According to the method and apparatus, a data offset byte (402) is determined for a frame of data to be transmitted. The data offset value is used to modify the data bytes of the data frame to insure that the modified data bytes does not include control bytes (320) which are sent with the data. The offset value and the modified data bytes are then sent (508) to a receiver which recovers (710) the data. Accordingly, only one offset byte must be transmitted for each frame of data.

Claims

1. A method for transmitting data in a frame having data bytes and control information, said method comprising the steps of:

selecting an offset value based upon the value of said data bytes compared to the value of said control information;

modifying said data bytes based upon said offset value, said modified data bytes being different from said control information; and

transmitting said modified data bytes.

2. The method for transmitting data according to claim 1 wherein said step of selecting an offset value comprises determining a value which, when used to modify said data bytes, will result in modified data bytes which are different from said control information.

3. The method for transmitting data according to claim 1 wherein said step of modifying said data bytes comprises subtracting said offset value from each said data byte.

4. The method for transmitting data according to claim 1 wherein said step of modifying said data bytes comprises providing an exclusive or operation with said data bytes and a predetermined value.

5. The method for transmitting data according to claim 1 wherein said step of transmitting further includes transmitting said offset value.

6. A method for transmitting data in a frame having at least one control byte, said method comprising the steps of:

partitioning said data into a plurality of data bytes;

analyzing each data byte of said plurality of data bytes to determine if a data byte corresponds to said at least one control byte;

calculating an offset value if a data byte of said plurality of data bytes corresponds to said at least one control byte;

modifying said data byte based upon said offset value such that said data byte as modified is different from said at least one control byte; and

transmitting said frame having said modified data byte.

7. The method for transmitting data according to claim 6 wherein said step of calculating an offset value comprises determining a value which, when used to modify said data byte, will result in a modified data byte which is different from said at least one control byte.

8. The method for transmitting data according to claim 7 wherein said step of modifying said data byte comprises subtracting said offset value from said data byte.

9. The method for transmitting data according to claim 7 further comprising a plurality of data bytes which correspond to a plurality of control bytes, wherein said step of calculating an offset value comprises determining a value which, when used to modify said plurality of data bytes, will result in modified data bytes which are different from said plurality of control bytes.

10. A method for transmitting data in a frame having a plurality of control bytes, said method comprising the steps of:

partitioning said data into a plurality of data bytes;

selecting an offset value which, when used to modify each data byte of said plurality of data bytes, creates modified data bytes which are different from each control byte of said plurality of controls bytes;

modifying each said data byte with said offset value for each said data byte respectively; and

transmitting said offset value and said modified data bytes.

11. A method for transmitting data in a frame and control bytes, said method comprising the steps of:

partitioning said data into data bytes;

selecting an offset value based upon the value of said data bytes compared to the value of said control bytes;

modifying said data bytes based upon said offset value, said modified data bytes being different from said control bytes;

transmitting said offset value and said modified data bytes from a transmitting station;

receiving said offset value and said modified data bytes; and

converting said modified data bytes to said data bytes based upon said offset value.

12. An apparatus for transmitting a data frame having at least one control byte, said apparatus comprising:

a processing circuit for calculating an offset value based upon the value of data bytes compared to the value of said control byte of a frame of said data bytes to be transmitted;

a data formatting circuit for generating said data frame having said offset value and modified data bytes; and

a transmitter for transmitting said data frame.

13. The apparatus for transmitting data according to claim 12 wherein said offset value comprises a value which, when used to modify said data bytes, will result in modified data bytes which are different from said at least one control byte.

14. The apparatus for transmitting data according to claim 12 wherein said modified data bytes comprise data bytes less said offset value.

15. The apparatus for transmitting data according to claim 12 wherein said modified data bytes comprise the result of an exclusive or of the data bytes and a predetermined value.

16. The apparatus for transmitting data according to claim 12 wherein said transmitter comprises an infrared transmitter.

17. The apparatus for transmitting data according to claim 16 further comprising a universal asynchronous receiver transmitter coupled between said processing circuit and said infrared transmitter.

18. An apparatus for transmitting data in a data frame having at least one control byte, said apparatus comprising:

a processing circuit for calculating an offset value based upon said data frame to be transmitted compared to the value of said control byte and for modifying bytes of data of said data frame;

a universal asynchronous receiver/transmitter coupled to said processing circuit for generating said data frame; and

a transmitter coupled to said universal asynchronous receiver/transmitter for transmitting said data frame.

19. An apparatus for transmitting a data frame having at least one control byte, said apparatus comprising:

a transmitting device having a first processing circuit for calculating an offset value of a frame of data bytes to be transmitted based upon said data frame compared to the value of said control byte, a universal asynchronous receiver/transmitter for generating said data frame having said offset value and modified data bytes, and a transmitter for transmitting said data frame; and

a receiving device having a receiver for receiving said data frame having said offset value and modified data bytes and a second processing circuit for recovering said data bytes based upon said offset value.