Processor modem

• US 4,965,641 A
• Filed: 05/17/1989
• Issued: 10/23/1990
• Est. Priority Date: 02/21/1989
• Status: Expired due to Term

• Current Assignee: CIF Licensing LLC, Universal Data Systems Incorporated Huntsville Al
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Bruce, Melvin, Polge, Steve, Windham, Danny, Blackwell, Steven R.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Chin, Stephen
• Application Number:
  US07/353,286
• Time in Patent Office: 524 Days
• Field of Search: 375/7, 375/8, 379/93, 379/94, 379/96, 379/97, 379/98, 364/708, 364/709, 364/710, 371/32, 371/49
• US Class Current: 375/219
• CPC Class Codes: H04L 27/00 Modulated-carrier systems

Abstract

An improved data terminal equipment (DTE)-modem arrangement is disclosed. In this arrangement, a single processor, such as one that resides within a DTE, both executes an application program and implements a modem. A DTE that utilizes this arrangement, therefore, needs only a single processor to perform both the application and modem functions.

Claims

1. A method for a processor having an application program and a modem program for receiving output data words from said application program and providing passband transmit signal values, said method comprising the following steps:

(a) determining when said application program has an output data word;

(b) receiving said output data word;

(c) writing said output data byte to a word buffer;

(d) determining when it is time to send a baseband transmit point;

(e) reading at least one information bit from said byte buffer;

(f) selecting a baseband transmit point based at least in part on said at least one information bit and a predetermined method for selecting a baseband transmit point based on at least one predetermined information bit;

(g) writing said baseband transmit point to a baud buffer;

(h) determining when it is time to send a passband transmit signal value;

(i) reading said baseband transmit point from said baud buffer;

(j) selecting a passband transmit signal value based at least in part on said baseband transmit point and a predetermined method for selecting a passband transmit signal value based on a predetermined baseband transmit point;

(k) providing said passband transmit signal value.

2. The method of claim 1 wherein said predetermined method for selecting a baseband transmit point based on at least one predetermined information bit is based at least in part on a predetermined modem constellation or eye pattern.

3. The method of claim 2 wherein said predetermined method for selecting a passband transmit signal value based on a predetermined baseband transmit point is based at least in part on a predetermined modem modulation method.

4. The method of claim 3 wherein step (k) includes providing said passband transmit signal value to line output means coupled to said processor.

5. The modem transmit method of claim 4 wherein said line output means comprises a D/A converter device and said passband transmit signal value comprises a digital sample value.

6. A method for a processor having an application program and a modem program for receiving passband receive signal values and providing input data words to said application program, said method comprising the following steps:

(a) determining when it is time to receive a passband receive signal value;

(b) receiving a passband receive signal value;

(c) selecting a baseband receive point based at least in part on said passband receive signal value and a predetermined method for selecting a baseband receive point based on a predetermined passband receive signal value;

(d) writing said baseband receive point to a sample buffer;

(e) determining when it is time to receive a baseband receive point;

(f) reading said baseband receive point from said sample buffer;

(g) selecting at least one information bit based at least in part on said baseband receive point and a predetermined method for selecting at least one information bit based on a predetermined baseband receive point;

(h) writing said at least one information bit to a baud buffer;

(i) determining when said baud buffer has an input data word;

(j) reading said input data word from said baud buffer;

(k) providing said input data word to said application program.

7. The method of claim 6 wherein said predetermined method for selecting a baseband receive point based on a predetermined passband receive signal value is based at least in part on a predetermined modem demodulation method.

8. The method of claim 7 wherein said predetermined method for selecting at least one information bit based on a predetermined baseband receive point is based at least in part on a predetermined modem constellation or eye pattern.

9. The method of claim 8 wherein said step (b) includes receiving said passband receive signal value from line input means coupled to said processor.

10. The modem receive method of claim 9 wherein said line input means comprises an A/D converter device and said passband receive signal value comprises a digital sample value.

11. A data terminal equipment (DTE) having a processor and line output means, said line output means coupled to said processor, said processor having an application program and modem program means for receiving output data words from said application program and providing passband transmit signal values to said line output means, said modem program means comprising:

first determining means for determining when said application program has an output data word;

receiving means responsive to said first determining means for receiving said output data word;

first writing means responsive to said receiving means for writing said output data word to a word buffer;

second determining means for determining when it is time to send a baseband transmit point;

first reading means responsive to said second determining means for reading at least one information bit from said byte buffer;

first selecting means responsive to said first reading means for selecting a baseband transmit point based at least in part on said at least one information bit and a predetermined method for selecting a baseband transmit point based on at least one predetermined information bit;

second writing means responsive to said first selecting means for writing said baseband transmit point to a baud buffer;

third determining means for determining when it is time to send a passband transmit signal value;

second reading means responsive to said third determining means for reading said baseband transmit point from said baud buffer;

second selecting means responsive to said second reading means for selecting a passband transmit signal value based at least in part on said baseband transmit point and a predetermined method for selecting a passband transmit signal value based on a predetermined baseband transmit point;

providing means responsive to said second selecting means for providing said passband transmit signal value to said line output means.

12. The DTE of claim 11 wherein said predetermined method for selecting a baseband transmit point based on at least one predetermined information bit is based at least in part on a predetermined modem constellation or eye pattern.

13. The DTE of claim 12 wherein said predetermined method for selecting a passband transmit signal value based on a predetermined baseband transmit point is based at least in part on a predetermined modem modulation method.

14. The DTE of claim 13 wherein said line output means comprises a D/A converter and said passband transmit signal value comprises a digital sample value.

15. A data terminal equipment (DTE) having a processor and line input means, said line input means coupled to said processor, said processor having an application program and modem program means for receiving passband receive signal values from said line input means and providing input data words to said application program, said modem program means comprising:

first determining means for determining when it is time to receive a passband receive signal value;

receiving means responsive to said first determining means for receiving a passband receive signal value from said line input means;

first selecting means responsive to said receiving means for selecting a baseband receive point based at least in part on said passband receive signal value and a predetermined method for selecting a baseband receive point based on a predetermined passband receive signal value;

first writing means responsive to said first selecting means for writing said baseband receive point to a sample buffer;

second determining means for determining when it is time to receive a baseband receive point;

first reading means responsive to said second determining means for reading said baseband receive point from said sample buffer;

second selecting means responsive to said first reading means for selecting at least one information bit based at least in part on said baseband receive point and a predetermined method for selecting at least one information bit based on a predetermined baseband receive point;

second writing means responsive to said second selecting means for writing said at least one information bit to a baud buffer;

third determining means for determining when said baud buffer has an input data word;

second reading means responsive to said third determining means for reading said input data word from said baud buffer;

providing means responsive to said second reading means for providing said input data word to said application program.

16. The DTE of claim 15 wherein said predetermined method for selecting a baseband receive point based on a predetermined passband receive signal value is based at least in part on a predetermined modem demodulation method.

17. The DTE of claim 16 wherein said predetermined method for selecting at least one information bit based on a predetermined baseband receive point is based at least in part on a predetermined modem constellation or eye pattern.

18. The DTE of claim 17 wherein said line input means comprises an A/D converter and said passband receive signal value comprises a digital sample value.