Apparatus and method for allocating OVSF codes and I/Q channels for reducing peak-to-average power ratio in transmitting data via enhanced up-link dedicated channels in WCDMA systems

• US 7,639,650 B2
• Filed: 02/14/2005
• Issued: 12/29/2009
• Est. Priority Date: 02/14/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Heo, Youn-Hyoung, Kim, Young-Bum, Kwak, Yong-Jun, Cho, Joon-Young, Lee, Ju-Ho
• Primary Examiner(s): Le; Nhan T
• Application Number:
  US11/057,618
• Publication Number:
  US 20050213677A1
• Time in Patent Office: 1,779 Days
• Field of Search: 375/140, 375/142, 375/145, 375/146, 375/147, 375/149, 370/328, 370/329, 370/335, 370/342
• US Class Current: 370/335
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 2201/70706 with means for reducing the peak-to-average power ratio
• CPC Class Codes: H04J 13/0044 OVSF [orthogonal variable spreading factor]
• CPC Class Codes: H04J 13/20 having an orthogonal variable spreading factor [OVSF]

Abstract

An apparatus and method in which an Enhanced Uplink Dedicated transport CHannel (EUDCH) is used in a Wideband Code Division Multiple Access (WCDMA) system is provided. In a User Equipment (UE), when physical channels for transmitting EUDCH data are transmitted in addition to existing physical channels, a Peak-to-Average Power Ratio (PAPR) of an uplink transport signal increases. The increase in PAPR depends upon Orthogonal Variable Spreading Factor (OVSF) codes allocated to the corresponding physical channels and In-phase/Quadrature-phase (I/Q) channels. Therefore, the apparatus and method allocate optimum OVSF codes and I/Q channels to EUDCH-related physical channels in order to minimize an increase in PAPR due to EUDCH.

Claims

1. A method for transmitting enhanced packet data in a mobile communication system, the method comprising the steps of:

generating a first enhanced dedicated physical data channel (E-DPDCH) through an in-phase (I) channel and a second E-DPDCH through a quadrature-phase (Q) channel if high speed downlink packet access (HSDPA) is set, and generating the first E-DPDCH through the Q channel and the second E-DPDCH through the I channel if HSDPA is not set;

generating an enhanced dedicated physical control channel (E-DPCCH) using the I channel; and

summing up the E-DPDCHs and the E-DPCCH before transmission.

2. The method of claim 1, wherein the E-DPCCH is spread with an orthogonal variable spreading factor (OVSF) code (256, 1) on the I channel before being transmitted.

3. The method of claim 1, wherein if one dedicated physical data channel (DPDCH) is set up, a high speed-downlink physical control channel (HS-DPCCH) is allocated to an OVSF code (256, 64) on the Q channel.

4. The method of claim 1, wherein if one dedicated physical data channel (DPDCH) is set up and if a spreading factor of the E-DPDCH is denoted by SF_E-DPDCH, an OVSF code (SF_E-DPDCH, SF_E-DPDCH/2) is allocated.

5. The method of claim 4, further comprising the step of, if SF_E-DPDCH is 2 and two E-DPDCHs are simultaneously transmitted, generating the first E-DPDCH and the second E-DPDCH which are spread with an OVSF code (2, 1) on the I channel and the Q channel, respectively.

6. The method of claim 4, further comprising the step of, if the DPDCH is not transmitted, generating third and fourth E-DPDCHs using an OVSF code (4, 1) on the I channel and the Q channel, respectively.

7. An apparatus for transmitting an enhanced packet data service in a mobile communication system, the apparatus comprising:

a controller for allocating a first enhanced dedicated physical data channel (E-DPDCH) to an in-phase (I) channel and a second E-DPDCH to a quadrature-phase (Q) channel if high speed downlink packet access (HSDPA) is set, and allocating the first E-DPDCH to the Q channel, the second E-DPDCH to the I channel if HSDPA is not set, and an enhanced dedicated physical control channel (E-DPCCH) to the I channel;

a spreader for spreading the E-DPDCHs and the E-DPCCH according to a control signal from the controller;

a summer for summing up the spread E-DPDCHs and E-DPCCH; and

a transmitter for transmitting the summed signal.

8. The apparatus of claim 7, wherein the controller allocates the E-DPCCH to an orthogonal variable spreading factor (OVSF) code (256, 1) on the I channel.

9. The apparatus of claim 7, wherein if one dedicated physical data channel (DPDCH) is set up, the controller allocates a high speed downlink physical control channel (HS-DPCCH) to an OVSF code (256, 64) on the Q channel.

10. The apparatus of claim 7, wherein if one dedicated physical data channel (DPDCH) is set up, the controller allocates the E-DPDCH to an OVSF code (SF_E-DPDCH, SF_E-DPDCH/2), where SF_E-DPDCH denotes a spreading factor of the E-DPDCH.

11. The apparatus of claim 10, wherein if SF_E-DPDCH is 2 and two E-DPDCHs are simultaneously transmitted, the controller allocates the first E-DPDCH and the second E-DPDCH to an OVSF code (2, 1) on the I channel and the Q channel, respectively.

12. The apparatus of claim 10, wherein if the DPDCH is not transmitted, the controller allocates third and fourth E-DPDCHs to an OVSF code (4, 1) on the I channel and the Q channel, respectively.