Method and architecture for TDMA receiver incorporating a unique word correlation control loop

• US 6,400,734 B1
• Filed: 12/07/1998
• Issued: 06/04/2002
• Est. Priority Date: 12/07/1998
• Status: Expired due to Term

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Weigand, David L.
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): PHAN, MAN U
• Application Number:
  US09/206,502
• Time in Patent Office: 1,275 Days
• Field of Search: 370/514, 370/486, 370/535, 370/326, 370/321, 370/322, 370/542, 370/544, 375/260, 375/340, 375/347, 375/349, 375/365, 375/364, 375/368
• US Class Current: 370/514
• CPC Class Codes: H04B 7/2681 Synchronisation of a mobile station with one base station
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 7/042 Detectors therefor, e.g. correlators, state machines digital correlators in general G06F17/15
• CPC Class Codes: H04W 56/0085 detecting a given structure in the signal

Abstract

A system includes a unique word correlator module which correlates a unique word field in a burst of a time division multiple access (TDMA) signal against a predefined marker sequence. Automatic timing control circuitry is coupled to the unique word correlator module. The automatic timing control circuitry derives a number of errors that are allowable during correlation of the unique word field.

Claims

1. A system comprising:

a unique word correlator module operable to correlate a unique word field in a burst of a time division multiple access (TDMA) signal against a predefined sequence; and

automatic timing control circuitry coupled to the unique word correlator module, the automatic timing control circuitry operable to derive a number of errors that are allowable during correlation of the unique word field, wherein the automatic timing control circuitry comprises correlation error calculation circuitry operable to determine the actual number of errors occurring during correlation of the unique word field.

2. A system comprising:

a unique word correlator module operable to correlate a unique word field in a burst of a time division multiple access (TDMA) signal against a predefined sequence; and

p1 automatic timing control circuitry coupled to the unique word correlator module, the automatic timing control circuitry operable to derive a number of errors that are allowable during correlation of the unique word field, wherein the automatic timing control circuitry comprises a correlation error comparator operable to compare the derived number of allowable errors against an actual number of errors occurring during correlation of the unique word field.

3. A system comprising:

a unique word correlator module operable to correlate a unique word field in a burst of a time division multiple access (TDMA) signal against a predetermined sequence, wherein the unique word correlator module is operable to support a dynamic window within which the unique word field is allowably detected; and

automatic timing control circuitry coupled to the unique word correlator module, the automatic timing control circuitry operable to derive a number of errors that are allowable during correlation of the unique word field.

4. A system comprising:

a unique word correlator module operable to correlate a unique word field in a burst of a time division multiple access (TDMA) signal against a predefined sequence; and

automatic timing control circuitry coupled to the unique word correlator module, the automatic timing control circuitry operable to derive a number of errors that are allowable during correlation of the unique word field, wherein the automatic timing control circuitry is operable to use a current value for at least one parameter to derive the number of allowable errors.

5. The system of claim 4 wherein the at least one parameter is a parameter from the group comprising received signal strength indicator level, preamble detection, CRC result, timebase status, and channel type for the TDMA signal.

6. A method comprising:

receiving a burst of a time division multiple access (TDMA) signal, the burst having a unique word field;

correlation the unique word field against a predefined sequence;

deriving a number of errors that are allowable during correlation of the unique word field; and

comparing the derived number of allowable errors against an actual number of errors occurring during correlation of the unique word field.

7. A method comprising:

receiving a burst of a time division multiple access (TDMA) signal, the burst having a unique word field;

correlation the unique word field against a predefined sequence; and

deriving a number of errors that are allowable during correlation of the unique word field, wherein deriving comprises using a current value for at least one parameter to derive the number of allowable errors.

8. The method of claim 7 wherein the at least one parameter is a parameter from the group comprising received signal strength indicator level, preamble detection, CRC result, timebase status, and channel type for the burst of the TDMA signal.