Method and apparatus for providing fast detection of a high speed shared control channel

• US 20060126548A1
• Filed: 02/09/2006
• Published: 06/15/2006
• Est. Priority Date: 02/13/2004
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Pietraski, Philip J., Tsai, Yingming, Sternberg, Gregory S.
• Granted Patent: US 7,639,644 B2
• Time in Patent Office: Days
• US Class Current: 370/310
• CPC Class Codes: H03M 13/3738 with judging correct decoding
• CPC Class Codes: H03M 13/41 using the Viterbi algorithm or Viterbi processors
• CPC Class Codes: H03M 13/653 3GPP HSDPA, e.g. HS-SCCH or DS-DSCH related
• CPC Class Codes: H04L 1/0054 Maximum-likelihood or sequential decoding, e.g. Viterbi, Fano, ZJ algorithms
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 1/20 using signal quality detector

Abstract

A method and apparatus for providing fast detection of a high speed shared control channel (HS-SCCH). The HS-SCCH carries information necessary for receiving data via a high speed downlink shared channel (HS-DSCH). The apparatus receives messages transmitted via a plurality of HS-SCCHs. The apparatus measures a channel quality for the messages received via each HS-SCCH. The apparatus performs a threshold test by comparing the channel quality with a predetermined threshold. The apparatus then selects a HS-SCCH having the best channel quality among the HS-SCCHs.

Claims

1. A method of providing fast detection of a high speed shared control channel (HS-SCCH), the method comprising:

(a) receiving downlink control messages including a last received downlink control message transmitted via a plurality of monitored HS-SCCHs;

(b) calculating an accumulated soft metric for each of the HS-SCCHs;

(c) determining that at least two of the accumulated soft metrics exceed a soft metric threshold and are close in value; and

(d) if one of the at least two accumulated soft metrics is associated with a particular one of the monitored HS-SCCHs used to receive the last received downlink control message, selecting a high-speed downlink shared channel (HS-DSCH) indicated by the particular monitored HS-SCCH to receive downlink messages.

2. The method of claim 1 wherein a downlink control message is received at a first time slot of a sub-frame of each HS-SCCH.

3. The method of claim 1 further comprising:

(e) generating a bit error rate (BER) for each HS-SCCH;

(f) comparing each BER to a predetermined threshold; and

(g) determining the HS-SCCH having the lowest BER.

4. A wireless transmit/receive unit (WTRU) for providing fast detection of a high speed shared control channel (HS-SCCH), the WTRU comprising:

(a) a plurality of decoders for receiving downlink control messages including a last received downlink control message transmitted via a plurality of monitored HS-SCCHs and calculating an accumulated soft metric for each of the HS-SCCHs;

(b) a threshold comparator which receives the calculated accumulated soft metrics from the decoders and determines that at least two of the accumulated soft metrics exceed a soft metric threshold and are close in value; and

(c) a selector for selecting a high-speed downlink shared channel (HS-DSCH) indicated by the particular monitored HS-SCCH to receive downlink messages, if one of the at least two accumulated soft metrics is associated with a particular one of the monitored HS-SCCHs used to receive the last received downlink control message.

5. The WTRU of claim 5 wherein a downlink control message is received at a first time slot of a sub-frame of each HS-SCCH.

6. The WTRU of claim 5 wherein each of the plurality of decoders includes a bit error rate (BER) calculation unit for generating a BER of a respective one of the monitored HS-SCCHs, and the threshold comparator compares each BER to a predetermined threshold to determine which one of the monitored HS-SCCHs has the lowest BER.

7. In a wireless transmit/receive unit (WTRU) for providing fast detection of a high speed shared control channel (HS-SCCH), an integrated circuit (IC) comprising:

(a) a plurality of decoders for receiving downlink control messages including a last received downlink control message transmitted via a plurality of monitored HS-SCCHs and calculating an accumulated soft metric for each of the HS-SCCHs;

(b) a threshold comparator which receives the calculated accumulated soft metrics from the decoders and determines that at least two of the accumulated soft metrics exceed a soft metric threshold and are close in value; and

(c) a selector for selecting a high-speed downlink shared channel (HS-DSCH) indicated by the particular monitored HS-SCCH to receive downlink messages, if one of the at least two accumulated soft metrics is associated with a particular one of the monitored HS-SCCHs used to receive the last received downlink control message.

8. The IC of claim 7 wherein a downlink control message is received at a first time slot of a sub-frame of each HS-SCCH.

9. The IC of claim 7 wherein each of the plurality of decoders includes a bit error rate (BER) calculation unit for generating a BER of a respective one of the monitored HS-SCCHs, and the threshold comparator compares each BER to a predetermined threshold to determine which one of the monitored HS-SCCHs has the lowest BER.