System for improved power savings during full DTX mode of operation in the downlink

• US 7,768,953 B2
• Filed: 10/18/2002
• Issued: 08/03/2010
• Est. Priority Date: 10/19/2001
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Terry, Stephen E., DiFazio, Robert A.
• Primary Examiner(s): Harper; Vincent P
• Assistant Examiner(s): Sabouri; Mazda
• Application Number:
  US10/273,478
• Publication Number:
  US 20030086381A1
• Time in Patent Office: 2,846 Days
• Field of Search: 370/345, 370/346, 370/347, 370/348
• US Class Current: 370/311
• CPC Class Codes: H04B 2201/70709 with discontinuous detection
• CPC Class Codes: H04B 7/2618 using hybrid code-time division multiple access [CDMA-TDMA]
• CPC Class Codes: H04B 7/2643 using time-division multiple access [TDMA] H04B7/2615, H04B7/2618 take precedence
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A system and method that achieve power savings by turning off all or some of the baseband processing for codes and timeslots that have not been transmitted due to full DTX. When full DTX is detected by reception of a Special Burst (SB), the receiver is turned off for all timeslots and frames for the duration of the Special Burst Scheduling Period (SBSP). The transmitter schedules transmissions following any idle period to start on the boundary of the SBSP. The receiver determines the SBSP and if the transmitter initiates transmissions according to SBSP by reception of several initial full DTX cycles.

Claims

1. A method for managing the transmission of data during discontinuous transmission (DTX) in a time division duplex (TDD) communication mode, the method comprising:

receiving a transport format combination index (TFCI) for a coded composite transport channel (CCTrCH) at a wireless transmit/receive unit (WTRU);

determining whether the received TFCI is a special burst (SB);

on a condition that the received TFCI is a SB, turning off receiver processing, and turning on the receiving processing at the start of a predetermined duration, the predetermined duration equal to a plurality of transmission time intervals (TTIs), wherein the predetermined duration is determined iteratively by initializing a timing value in response to the TFCI indicating a SB, incrementing the timing value by a duration of TTIs until a next TFCI indication of an SB is received, and storing the duration of TTIs as the predetermined duration;

on a condition that the received TFCI is not a SB, processing data associated with the TFCI; and

reading a next TFCI.

2. The method of claim 1 wherein the determining is repeated for the next TFCI.

3. An apparatus configured to save power during discontinuous transmission (DTX), the apparatus comprising:

a preprocessing unit configured to determine whether a received signal includes a valid transport format combination index (TFCI);

a detection unit configured to read the valid TFCI to determine whether the TFCI is a special burst (SB); and

a learning unit configured to determine when data will be transmitted, and for turning off receiver processing for all codes and timeslots that will not be used, and turning on receiver processing following a predetermined duration equal to a plurality of transmission time intervals (TTIs), where the learning unit learns the predetermined duration by initializing a timing value in response to the TFCI indicating a SB, incrementing the timing value by a duration of TTIs until a next TFCI indication of an SB is received, and storing the duration of TTIs as the predetermined duration.

4. The apparatus of claim 3 wherein the preprocessing unit comprises a code power estimation unit configured to estimate the power of the received signal.

5. The apparatus of claim 4 wherein the processing unit further comprises a burst quality estimation unit configured to estimate a quality of the received signal.

6. The apparatus of claim 3 wherein the detection unit comprises an end of DTX detection unit configured to read the valid TFCI and identify whether data is being transmitted.

7. The apparatus of claim 6 wherein the detection unit further comprises a SB detection unit configured to read the valid TFCI and identifying whether it is a SB indicating full DTX.

8. The apparatus of claim 3, wherein the learning unit:

reads each TFCI received, and on a condition that the received TFCI is not a SB, sends data for processing;

on a condition that the read TFCI is a not SB, the learning unit increments the timing value by the TTI; and

on a condition that the read TFCI is a SB, the timing value is stored as a Special Burst Storage Parameter (SBSP) and the SBSP is set as the predetermined duration.