AU2013200839A1 - Generation of user equipment identification. - Google Patents

Abstract

A base station for use in a code division multiple access communication system, the base station including: 5 circuitry configured to process a user equipment identification (UE ID) by 12 rate convolutionally encoding the UE ID to produce a code used by the base station for scrambling a high speed shared control channel (HS-SCCH), wherein the base station is configured to transmit a wireless signal, the wireless signal providing the user equipment with payload data carried on a high 10 speed physical downlink shared channel (HS-PDSCH), the HS-PDSCH being associated with the HS-SCCH

Description

1 GENERATION OF USER EQUIPMENT IDENTIFICATION SPECIFIC SCRAMBLING CODE FOR THE HIGH SPEED SHARED CONTROL CHANNEL BACKGROUND The present invention relates to wireless communication systems. More 5 particularly, the present invention relates to user equipment identification specific scrambling sequences for high speed shared control channels (HS-SCCH). A high speed downlink packet access (HSDPA) is proposed for wideband code division multiple access communication systems. HSDPA allows for high downlink data rates to support multimedia services. 10 To support HSDPA, high speed shared control channels (HS-SCCHs) are used. The HS-SCCHs are used to signal vital control information to the user equipments (UEs). Each HS-SCCH has two parts, referred to as Part-1 and Part 2. Part-1 carries time critical information needed by the UE. This information includes the channelization code set and the modulation type used by the high 15 speed physical downlink shared control channel (HS-PDSCH) which carries the HSDPA payload. This information is vital to support HSDPA, since HSDPA uses adaptive modulation and coding (AMC). To obtain its Part-1 information, each HSDPA UE monitors up to four HS SCCHs for its information. The information for a particular UE is distinguished 20 from other UEs by its UE identification (UE ID) specific scrambling sequence. The UE processes each monitored HS-SCCH with its UE ID specific scrambling sequence to detect the HS-SCCH intended for the UE. After processing, the UE determines on which HS-SCCH, if any, information was carried using its scrambling sequence. The UE descrambles the data carried on Part-1 of its HS 25 SCCH using its scrambling sequence. Until recently, a 10 bit UE ID was used as the basis for the UE ID specific scrambling sequence. In this case, this UE ID was converted into a 40 bit scrambling sequence. To turn the 10 bit UE ID into the 40 bit UE ID specific scrambling sequence, the 10 bit UE ID is processed by a Reed-Muller block to 30 produce a 32 bit code. The first 8 bits of the produced code are repeated and appended onto the back of the 32 bit code to produce a 40 bit code. Although it is proposed to extend the UE ID length to 16 chips, the current proposal for the HS-SCCHs uses a 10 bit UE ID. This UE ID is converted into a 2 40 bit scrambling sequence. To turn the 10 bit UE ID into the 40 bit scrambling sequence, the 10 bit UE ID is processed by a Reed-Muller block to produce a 32 bit code. The first 8 bits of the produced code are repeated and appended onto the back of the 32 bit code to produce a 40 bit code. 5 To reduce the occurrence of false detections, it is desirable to have good separation between the produced scrambling codes for each UE ID. Accordingly, it is desirable to have alternate approaches to producing scrambling codes. SUMMARY OF THE INVENTION A code is produced for use in scrambling or descrambling data associated 10 with a high speed shared control channel (HS-SSCH) for a particular user equipment. A user identification of the particular user equipment includes L bits. A rate convolutional encoder processes at least the bits of the user identification by a rate convolutional code to produce the code. According to a first aspect the present invention provides a wideband code 15 division multiple access (WCDMA) user equipment (UE) including: circuitry configured to process a high speed shared control channel (HS-SCCH); and circuitry configured to process a high speed physical downlink shared channel (HS-PDSCH) associated with the HS-SCCH when the HS-SCCH includes information processed with a user specific scrambling sequence associated with 20 the UE; wherein the user specific scrambling sequence is a result of a 1/2 rate convolutional encoding of a UE identification (ID). According to another aspect the present invention provides a method including: processing a high speed shared control channel (HS-SCCH) by a wideband code division multiple access (WCDMA) user equipment (UE); and 25 processing a high speed physical downlink shared channel (HS-PDSCH) associated with the HS-SCCH by the UE when the HS-SCCH includes information processed with a user specific scrambling sequence associated with the UE; wherein the user specific scrambling sequence is a result of a 1/2 rate convolutional encoding of a UE identification (ID). 30 According to a further aspect the present invention provides a user equipment including: an input configured to accept a 16 bit user identification; and a 1/2 rate convolutional encoder for processing the 16 bit user identification code with eight appended zero bits to produce a 48 bit code wherein the 48 bit code is 3 used to determine control information carried over a high speed shared control channel (HS-SCCH). According to yet another aspect the present invention provides an apparatus including: an input configured to accept a user identification including L 5 bits; and a 1/2 rate convolutional encoder for processing at least the bits of the user identification by a 1/2 rate convolutional code to produce a code used for scrambling a high speed shared control channel (HS-SCCH). According to yet another aspect the present invention provides a user equipment including: an input configured to accept a 16 bit user identification; and 10 a 1/2 rate convolutional encoder for processing the 16 bit user identification code with eight appended zero bits to produce a 48 bit code for use in descrambling a high speed shared control channel (HS-SCCH). According to still another aspect the present invention provides a user equipment including: an input configured to accept a 16 bit user identification; and 15 means for 1/2 rate convolutional encoding the 16 bit user identification code with eight appended zero bits to produce a 48 bit code for use in descrambling a high speed shared control channel (HS-SCCH). According to yet another aspect the present invention provides a base station including: an input configured to accept a 16 bit user identification; and a 20 1/2 rate convolutional encoder for processing the 16 bit user identification code with eight appended zero bits to produce a 48 bit code for use in scrambling a high speed shared control channel (HS-SCCH) for a user equipment associated with the 16 bit user identification. According to a further aspect the present invention provides a base station 25 including: an input configured to accept a 16 bit user identification; and means for 1/2 rate convolutional encoding the 16 bit user identification code with eight appended zero bits to produce a 48 bit code for use in scrambling a high speed shared control channel (HS-SCCH) for a user equipment associated with the 16 bit user identification. 30 BRIEF DESCRIPTION OF THE DRAWINGS Figure IA is a preferred diagram of a circuit for producing a code associated with a particular user for a HS-SCCH.

3a Figure 1B is a diagram of a rate matching block used in conjunction with Figure 1A. Figure 2A is a preferred diagram of a circuit for producing a code 5 associated with a user identification of 16 bits. Figure 2B is a diagram of a rate matching block used in conjunction with Figure 2A. Figure 3 is a simplified user equipment using the UE ID specific scrambling code. 10 Figure 4 is a simplified base station using the UE ID specific scrambling code. DESCRIPTION OF PREFERRED EMBODIMENT Although the preferred embodiments are described in conjunction with the preferred application of the invention for use with the HSDPA of the third 15 generation partnership project (3GPP) wideband code division multiple access (W-CDMA) communication system, the invention can be applied to other code 4 division multiple access communication systems. Figures 1A and 1B are diagrams of a preferred UE ID specific scrambling sequence circuit. A UE ID, XUE, of length L is input into the circuit. L can be any length, such as 8 bits, 10 bits, 16 bits, etc. The UE ID, XUE = {XUE1, ... , XUEL}, is input into a 12 rate 5 convolutional encoder 10 as shown in Figure 1A. Along with the UE ID, extra bits, such as zeros, may be added to the end of the input string to extend the length of the input string and, accordingly, the output string. The use of a 2 rate convolutional encoder 10 provides for a high level of code separation between the output strings produced by different UE IDs. Additionally, current proposed 3GPP 10 W-CDMA communication systems utilize a 2 rate convolutional encoder 10 for a forward error correction (FEC) technique. Accordingly, no additional hardware is required to generate the convolutionally encoded UE ID specific scrambling sequence. After encoding, based on the length of the output string, a rate matching stage 12 may be added to puncture bits to obtain a desired string 15 length. Figures 2A and 2B are diagrams of preferred UE ID specific scrambling sequence circuit for a preferred UE ID codes of length 16, L=16. The 16 bit UE ID, XUE ={XUE1, ... , XUE16}, is input into a 1/2 rate convolutional encoder 14 along with eight zero bits appended onto the end of the input string. As a result, the 20 input string is XUE1, ... ; XUE16; 0, 0, 0, 0, 0, 0, 0, 0. After being processed by the 12 rate convolutional encoder 14, the output code is 48 bits in length, CUE ={CUE1, CUE48}. To reduce the length of the code to a preferred length of 40 bits, eight bits are preferably punctured. Figure 2B illustrates the rate matching stage 16 to 25 perform the puncturing. After the rate matching stage 16, the effective length of the scrambling code is 40 bits. Figure 4 is a simplified diagram of a user equipment descrambling a HS SCCH using the UE ID specific scrambling code. The UE ID scrambling code is mixed, such as by exclusive-or gate 18, with the received HS-SCCH for use in 30 recovering the encoded HS-SCOH data. Figure 3 is a simplified diagram of a base station scrambling encoded data with the UE ID specific scrambling code for transfer over the HS-SCCH. The encoded data is mixed with the UE ID scrambling code, such as by an exclusive- 5 or gate 20, for a particular user. The scrambled data is used to produce the HS SCCH for transfer to the particular user.

Claims (34)

1. A wideband code division multiple access (WCDMA) user equipment (UE) including: circuitry configured to process a high speed shared control channel (HS-SCCH); and circuitry configured to process a high speed physical downlink 5 shared channel (HS-PDSCH) associated with the HS-SCCH when the HS-SCCH includes information processed with a user specific scrambling sequence associated with the UE; wherein the user specific scrambling sequence is a result of a 1/2 rate convolutional encoding of a UE identification (ID).

2. The WCDMA UE of claim 1 wherein the circuit configured to process the 10 HS-SCCH determines channelization and modulation information of the HS PDSCH when the HS-SCCH includes information processed with the user specific scrambling sequence.

3. The WCDMA UE of claim 1 wherein the user specific scrambling sequence is a result of rate matching the 1/2 rate convolutionally encoded UE ID. 15

4. The WCDMA UE of claim 1 wherein the HS-SCCH includes control data combined with the user specific scrambling sequence.

5. The WCDMA UE of claim 4 wherein the control data is convolutionally encoded.

6. The WCDMA UE of claim 1 wherein the associated HS-PDSCH is not 20 processed when the HS-SCCH does not include information processed with the user specific scrambling sequence.

7. The WODMA UE of claim I including circuitry configured to produce the user specific scrambling sequence. 25 7

8. The WCDMA UE of claim 7 wherein the circuitry configured to produce the user specific scrambling sequence comprises a 1/2 rate convolutional encoder.

9. A method including: processing a high speed shared control channel (HS SCCH) by a wideband code division multiple access (WCDMA) user equipment 5 (UE); and processing a high speed physical downlink shared channel (HS PDSCH) associated with the HS-SCCH by the UE when the HS-SCCH includes information processed with a user specific scrambling sequence associated with the UE; wherein the user specific scrambling sequence is a result of a 1/2 rate convolutional encoding of a UE identification (ID).

10 10. The method of claim 9 including determining by the UE channelization and modulation information of the HS-PDSCH when the HS-SCCH includes information processed with the user specific scrambling sequence.

11. The method of claim 9 wherein the user specific scrambling sequence is a result of rate matching the 1/2 rate convolutionally encoded UE ID. 15

12. The method of claim 9 wherein the HS-SCCH includes control data combined with the user specific scrambling sequence.

13. The method of claim 12 wherein the control data is convolutionally encoded.

14. The method of claim 9 wherein the associated HS-PDSCH is not 20 processed when the HS-SCCH does not include information processed with the user specific scrambling sequence.

15. The method of claim 9 including producing the user specific scrambling sequence.

16. A user equipment including: an input configured to accept a 16 bit user 25 identification; and a 1/2 rate convolutional encoder for processing the 16 bit user identification code with eight appended zero bits to produce a 48 bit code wherein 8 the 48 bit code is used to determine control information carried over a high speed shared control channel (HS-SCCH).

17. The user equipment of claim 16 further including a rate matching block for puncturing eight bits after the production of the 48 bit code. 5

18. The user equipment of claim 16 wherein the control information is used for decoding a high speed physical downlink shared channel (HS-PDSCH).

19. The user equipment of claim 18 wherein the HS-PDSCH is associated with the HS-SCCH.

20. An apparatus including: an input configured to accept a user identification 10 including L bits; and a 1/2 rate convolutional encoder for processing at least the bits of the user identification by a 1/2 rate convolutional code to produce a code used for scrambling a high speed shared control channel (HS-SCCH).

21. The apparatus of claim 20 further including a rate matching block for puncturing bits after the production of the 1/2 rate convolutional code. 15

22. A user equipment including: an input configured to accept a 16 bit user identification; and a 1/2 rate convolutional encoder for processing the 16 bit user identification code with eight appended zero bits to produce a 48 bit code for use in descrambling a high speed shared control channel (HS-SCCH).

23. The user equipment of claim 22 further including a rate matching block for 20 puncturing eight bits after the production of the 48 bit code.

24. A user equipment including: an input configured to accept a 16 bit user identification; and means for 1/2 rate convolutional encoding the 16 bit user identification code with eight appended zero bits to produce a 48 bit code for use in descrambling a high speed shared control channel (HS-SCCH). 9

25. The user equipment of claim 24 further including means for puncturing eight bits after the production of the 48 bit code.

26. A base station including: an input configured to accept a 16 bit user identification; and a 1/2 rate convolutional encoder for processing the 16 bit user 5 identification code with eight appended zero bits to produce a 48 bit code for use in scrambling a high speed shared control channel (HS-SCCH) for a user equipment associated with the 16 bit user identification.

27. The base station of claim 26 further including a rate matching block for puncturing eight bits after the production of the 48 bit code. 10

28. A base station including: an input configured to accept a 16 bit user identification; and means for 1/2 rate convolutional encoding the 16 bit user identification code with eight appended zero bits to produce a 48 bit code for use in scrambling a high speed shared control channel (HS-SCCH) for a user equipment associated with the 16 bit user identification. 15

29. The base station of claim 28 further including means for puncturing eight bits after the production of the 48 bit code.

30. The WCDMA EU of claim 1 and substantially as hereinbefore described with reference to the accompanying figures.

31. The method of claim 9 and substantially as hereinbefore described with 20 reference to the accompanying figures.

32. The user equipment of claim 16, 22 or 24, and substantially as hereinbefore described with reference to the accompanying figures.

33. The apparatus of claim 20 and substantially as hereinbefore described with reference to the accompanying figures. 10

34. The base station of claim 26 or claim 28 and substantially as hereinbefore described with reference to the accompanying figures. INTERDIGITAL TECHNOLOGY CORPORATION WATERMARK PATENT & TRADE MARK ATTORNEYS P2481IAUO4