HK1183998A - A wireless transmit/receive unit, a node-b and a method implemented in a node-b - Google Patents

Abstract

The present invention provided a wireless transmit/receive unit (WTRU), a Node-B and a method implemented in a Node-B. The WTRU comprises: a processor configured to receive a high speed downlink packet access (HSDPA) signal, wherein the received HSDPA signal includes data and a masked cyclic redundancy check (CRC) field, the processor further configured to damask the masked CRC field using WTRU ID bits and perform a CRC check with the data and a de-masked CRC field, wherein the CRC field and the WTRU ID bits are of different length.

Description

Wireless transmitting/receiving unit, node B and method implemented in node B

The present application is a divisional application of the chinese patent application entitled "method and apparatus for encoding and decoding high speed shared control channel data" filed 30/10/2007 under the application number 200780040594.7.

Technical Field

The present invention relates to wireless communications.

Background

In high speed downlink packet access (HSPDA) of the third generation partnership project (3 GPP), control information necessary for decoding a high speed downlink shared channel (HS-DSCH) is transmitted via a high speed shared control channel (HS-SCCH). Multiple HS-SCCHs may be transmitted to a set of wireless transmit/receive units (WTRUs) associated with a particular cell. The HS-SCCH carries two (2) parts of data: part 1 data and part 2 data. The part 1 data includes channelization code set information, modulation scheme information, and the like. Part 2 data includes transport block size information, hybrid automatic repeat request (HARQ) processing information, redundancy and constellation version information, WTRU Identification (ID), and the like. The HS-SCCH frame includes three time slots. Part 1 data is transmitted in the first time slot and part 2 data is transmitted in the second and third time slots.

Figure 1 shows a conventional HS-SCCH encoding. Channelization code setting information X for coded part 1 data_ccsAnd modulation scheme information X_msIs multiplexed to generate a bit sequence X₁. Convolutional encoding of rate 1/3 is applied to bit sequence X₁To generate a bit sequence Z₁. Bit sequence Z₁Punctured (puncturing) for rate matching to generate a bit sequence R₁. Rate matched bits R₁Masked in a WTRU-specific manner using a WTRU ID to generate a bit sequence S₁. Masking here means that each bit is conditionally flipped depending on the value of the mask bit. For WTRU-specific masking (WTRU-specific masking), the middle codeword bits are generated by encoding the WTRU ID with a convolutional coding of rate 1/2.

For coded part 2 data, block size information X is transmitted_tbsHARQ process information X_hapRedundant version information X_rvAnd new data indicator X_ndIs multiplexed to generate a bit sequence X₂. Cyclic Redundancy Check (CRC) bits from bit sequence X₁And X₂Is calculated. WTRU ID (X) for CRC bits_ue) A mask, then appended to the bit sequence X₂To form a bit sequence Y. Convolutional encoding of rate 1/3 is applied to bit sequence Y to generate bit sequence Z₂. Bit sequence Z₂Punctured for rate matching to generate a bit sequence R₂. Bit sequence S₁And R₂Are combined and mapped to physical channels for transmission.

The performance of part 1 data detection is affected by the hamming distance between the masks for the multiple HS-SCCHs. The conventional method generates a set of masks with a minimum distance of eight (8). When these minimum distance codes are used, the HS-SCCH detection performance is not optimal. In addition, in case of Multiple Input Multiple Output (MIMO) implementation for HSDPA, the HS-SCCH needs to carry more data. Therefore, more space must be made for data transmission related to the MIMO implementation in HS-SCCH.

Disclosure of Invention

A method and apparatus for encoding and decoding data for HS-SCCH is disclosed. For part 1 data encoding, the mask may be generated using the WTRU ID and the generator matrix with the largest minimum hamming distance. For part 2 data encoding, CRC bits are generated based on part 1 data and part 2 data. The number of CRC bits may be less than the WTRU ID. The CRC bits and/or part 2 data are masked with a mask. The mask may be a WTRU ID or a punctured WTRU ID of length equal to the CRC bits. The mask may be generated using the WTRU ID and the generator matrix with the largest minimum hamming distance. The masking may be performed after encoding or rate matching.

The present invention provides a wireless transmit/receive unit (WTRU) comprising: a processor configured to receive a High Speed Downlink Packet Access (HSDPA) signal, wherein the received HSDPA signal comprises data and a masked Cyclic Redundancy Check (CRC) field, the processor further configured to unmask the masked CRC field with WTRU ID bits, and perform a CRC check with the data and the unmasked CRC field, wherein the CRC field and the WTRU ID bits have different lengths.

The present invention also provides a node B, including: a processor configured to: retrieving Cyclic Redundancy Check (CRC) bits from a data block; masking the CRC bits with wireless transmit/receive unit (WTRU) Identification (ID) bits of a WTRU for which the data block is intended, wherein the CRC bits and the WTRU ID bits have different lengths; attaching the masked CRC bits to the data block; and transmitting the data and the masked CRC bits via a physical channel for transmission as a High Speed Downlink Packet Access (HSDPA) signal.

The present invention also provides a method implemented in a node B, the method comprising: retrieving Cyclic Redundancy Check (CRC) bits from the data block; masking the CRC bits with wireless transmit/receive unit (WTRU) Identification (ID) bits of a WTRU for which the data block is intended, wherein the CRC bits and the WTRU ID bits have different lengths; attaching the masked CRC bits to the data block; and transmitting the data block and the masked CRC bits via a physical channel for transmission as a High Speed Downlink Packet Access (HSDPA) signal.

Drawings

The invention will be understood in more detail from the following description, given by way of example and understood in conjunction with the accompanying drawings, in which:

figure 1 shows a conventional HS-SCCH encoding;

FIG. 2 is a block diagram of an example node B for encoding data for an HS-SCCH;

figure 3 is a block diagram of an example WTRU for decoding HS-SCCH data; and

figure 4 shows the simulation results of the selection error probability v. signal-to-noise ratio (SNR) of part 1 data comparing the performance of two HS-SCCH masking methods (prior art and present invention) where the two HS-SCCH codes are transmitted with different masking distances specified by the corresponding method.

Detailed Description

A "WTRU" as referred to hereinafter includes, but is not limited to, a User Equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a Personal Digital Assistant (PDA), a computer, or any other type of user equipment capable of operating in a wireless environment. Reference hereinafter to a "node B" includes, but is not limited to, a base station, a site controller, an Access Point (AP), or any other type of interfacing device capable of operating in a wireless environment.

Fig. 2 is an exemplary block diagram of a node B200 for encoding data for an HS-SCCH. The node B200 includes an encoder 202, a rate matching unit 204, a masking unit 206, a multiplexer 210, a CRC unit 212, a masking unit 214, an encoder 218, a rate matching unit 220, and a transceiver 224. The data for the HS-SCCH includes part 1 data and part 2 data. The part 1 data is sent to the encoder 202. The encoder 202 performs channel coding on the part 1 data 201. Then, the rate matching unit 204 punctures the channel-encoded part 1 data 203 for rate matching. Then, the masking unit 206 masks the rate-matched part 1 data 205 with a mask. The mask may be generated based on the WTRU ID 208.

The codes are typically chosen for their performance and for the simplicity of the decoder. Convolutional codes are a good example of codes that perform well and have low decoder complexity. Of course, there is some trade-off between performance and decoder complexity. However, since the corresponding decoder need not be present in the WTRU, decoder complexity is not a factor when selecting a code for masking. All that is needed is the mask itself, which can be created by a much simpler encoder.

The masking unit 206 generates the mask by block encoding the WTRU ID208 with a generator matrix that produces the mask with the largest minimum hamming distance. The mask is generated by a vector-matrix product of the WTRU ID and the generator matrix. The resulting mask is a linear combination of rows of the generator matrix. An example generator matrix for the (40, 16) code is given below. It should be noted that the generator matrix shown below is provided as an example, not as a limitation, and any other generator matrix may be used instead. In this example, the mask is a 40 bit mask and the WTRU ID is 16 bits in length. This example uses a block code with a prescribed generator matrix that produces a mask with a shortest distance of twelve (12). This provides much better performance when multiple HS-SCCH transmissions are used at the shortest distance.

[1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 0 1 0 0 1 1 1 0 0 1 0 0 1 1 1 0]

[0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 1 0 0 1 0 1 0 1 0 0 0 1 1 1 0 0 1 0 0 1]

[0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 1 0 0 1 0 1 0 1 0 0 0 1 1 1 0 0 1 0 1]

[0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 1 0 0 1 0 1 0 1 0 0 0 1 1 1 0 0 1 1]

[0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 1 1 1 1 0 1 0 1 1 1 0 0 1 1 0 1 0 1 1 0]

[0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 1 1 1 1 0 1 1 0 0 0 1 0 0 0 0 1 0 1]

[0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 1 1 1 1 0 1 1 0 0 0 1 0 0 0 0 1 1]

[0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 1 1 1 1 0 0 1 0 0 0 0 0 0 0 1 1 0 0 1 1 1 0]

[0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 1 0 0 1 0 0 0 1 1 0 1 1 0 1 0 0 0 1 0 0 1]

[0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 1 0 0 1 0 0 0 1 1 0 1 1 0 1 0 0 0 1 0 1]

[0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 1 0 0 1 0 0 0 1 1 0 1 1 0 1 0 0 0 1 1]

[0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 1 0 1 1 0 0 0 1 1 0 0 0 0 0 0 1 1 1 1 1 0]

[0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 1 0 0 0 1 1 1 0 1 1 0 1 1 1 0 1 1 1 1 0 0 0 1]

[0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 1 0 0 0 1 1 1 0 1 1 0 1 1 1 0 1 1 1 1 0 0 1]

[0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 1 0 0 0 1 1 1 0 1 1 0 1 1 1 0 1 1 1 1 0 1]

[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 1 0 0 0 1 1 1 0 1 1 0 1 1.1 0 1 1 1 1 1]

Conventionally, the mask is generated by encoding the WTRU ID208 with a convolutional code of rate 1/2. The minimum hamming distance for a conventional mask is eight (8). The improved hamming distance of the mask generated by the present invention results in improved performance of the partial 1 HS-SCCH decoder at the WTRU. Figure 4 shows the simulation results of the selection error probability v. signal-to-noise ratio (SNR) of part 1 data comparing the performance of two HS-SCCH masking methods (prior art and present invention) where the two HS-SCCH codes are transmitted with different masking distances specified by the corresponding method. Fig. 4 shows the performance improvement when using masks with twelve (12) hamming distances compared to masks with eight (8) hamming distances.

Referring again to fig. 2, part 1 data 201 and part 2 data 211 are sent to CRC unit 212 to calculate CRC bits. The CRC bits are appended to the part 2 data 211. The number of CRC bits may be less than the length of the WTRU ID, so more data (e.g., data for MIMO) may be included as part 2 data. The combined part 2 data and CRC bits 213 are sent to a masking unit 214. The masking unit 214 performs masking on the CRC bits or the CRC bits plus a part or all of the part 2 data with a mask, which will be described in detail below. The encoder 218 encodes the masked part 2 data and CRC bits 217. Rate matching unit 220 punctures the encoded part 2 data and CRC bits 219. Rate matched part 2 data and CRC bits 221 and rate matched part 1 data 209 are multiplexed by multiplexer 210 and sent to transceiver 224 for transmission.

According to one embodiment, masking unit 214 may generate a mask having a size equal to or less than the size of the CRC bits plus part 2 data. A portion of the mask is extracted and applied to the CRC bits, while the remainder of the mask is applied to all or part of the part 2 data. The mask may be generated using the WTRU ID216 and a generator matrix as disclosed above with respect to the masking to maximize the portion 1 data of the minimum hamming distance of the mask.

According to another embodiment, the WTRU ID may be used as a mask. The length of the WTRU ID may be longer than the CRC bits. Thus, a portion of the WTRU ID is used to mask the CRC bits, while the remainder of the WTRU ID is used to mask the part 2 data. According to yet another embodiment, the WTRU ID is punctured to the same length as the CRC bits and the punctured WTRU ID is used to mask the CRC bits.

According to yet another embodiment, the masking unit 214 may be moved between the encoder and the rate matching unit. The masking unit 214 generates a mask having a length equal to the rate-matched part 2 data and CRC bits 221. Masking unit 214 then applies the mask to the encoded part 2 data and CRC bits 219. Alternatively, the masking unit 214 may be moved between the rate matching unit 220 and the multiplexer 210 and the mask applied to the rate matched part 2 data and the CRC bits 221. The mask length may be 80 bits. With respect to part 1 data masked to maximize the minimum hamming distance of the mask, the mask may be generated using the WTRU ID216 and a generator matrix, as disclosed above.

Figure 3 is a block diagram of an example WTRU 300 for decoding HS-SCCH data. WTRU 300 includes a transceiver 302, a demultiplexer 304, a unmasking unit 306, a rate dematching unit 310, a decoder 312, a rate dematching unit 314, a decoder 316, a unmasking unit 318, and a CRC unit 322. The transceiver 302 receives an HS-SCCH transmission 301, the HS-SCCH transmission 301 including a first portion of the HS-SCCH frame at a first time slot corresponding to part 1 data and a second portion of the HS-SCCH frame at second and third time slots corresponding to part 2 data. The first part 305a and the second part 305b are demultiplexed by the demultiplexer 304.

The first portion 305a is unmasked by a unmasking unit 306. The unmasking unit 306 likewise generates the same mask used at the node B with the WTRU ID 308. The mask may be generated with the WTRU ID 308 and the generator matrix as described above. The rate dematching unit 310 restores the puncturing performed at the node B on the unmasked first portion 309. The rate dematching first portion 311 is then decoded by decoder 312 to output portion 1 data 313. Part 1 data is also sent to CRC unit 322.

The second portion 305B is rate dematching by the rate dematching unit 314 to restore the puncturing performed at the node B. The decoder 316 then decodes the rate demapped second portion 315 to output part 2 data (which may or may not be masked at the node B) and masked CRC bits 317. The unmasking unit 318 unmasks the masked CRC bits and selectively unmasks the masked part 2 data 317. The unmasking unit 318 unmasks using the same mask used at the node B. The mask may be the WTRU ID 320, a punctured WTRU ID, or a mask generated using the WTRU ID 320 and a generator matrix. The unmasking unit 318 outputs the unmasked part 2 data and the CRC bits 321 to the CRC unit 322. Then, the CRC unit 322 performs CRC check with the part 1 data 313, the part 2 data, and the CRC bits.

Depending on the masking scheme performed at the node B, the unmasking unit 318 may be moved between the decoder 316 and the rate dematching unit 314, or between the rate dematching unit 314 and the demultiplexer 304. In this case, the mask length may be 80 bits, and the mask may be generated with the wtru id216 and the generator matrix as described above to maximize the minimum hamming distance of the mask.

Examples

1. A node B for encoding HS-SCCH part 2 data.

2. The node-B of embodiment 1 comprising a CRC unit to generate CRC bits based on the part 1 data and the part 2 data, the CRC bits being appended to the part 2 data, the number of CRC bits being less than a WTRU Identity (ID).

3. The node-B of embodiment 2 comprising a masking unit to perform WTRU-specific masking of at least one of the part 2 data and the CRC bits with a mask.

4. The node-B of embodiment 3 comprising a transmitter to transmit the part 1 data and the part 2 data with the appended CRC bits after the WTRU-specific masking.

5. The node-B as in any of embodiments 3-4, wherein the mask is a punctured WTRU ID of length equal to the CRC bits.

6. The node-B of any of embodiments 3-5 wherein the mask is the WTRU ID and a portion of the WTRU ID is used to mask the CRC bits and the remaining portion of the WTRU ID is used to mask the part 2 data.

7. The node-B of any of embodiments 3-6 wherein the masking unit generates a mask of the largest minimum hamming distance using the wtru id and the generator matrix.

8. The node B according to any of embodiments 3-7, further comprising a channel encoder for performing channel coding on the part 2 data and the CRC bits.

9. The node-B of embodiment 8 comprising a rate matching unit to perform rate matching on the coded part 2 data and the CRC bits, wherein the masking unit generates a mask of length equal to the rate matched coded part 2 data and CRC bits, and performs WTRU-specific masking after one of channel coding and rate matching.

10. A WTRU for decoding part 2 data of an HS-SCCH.

11. The WTRU of embodiment 10 comprising a receiver for receiving part 1 data and part 2 data with appended CRC bits on the HS-SCCH, the number of CRC bits being less than the WTRU id, at least one of the part 2 data and the CRC bits being masked with a mask.

12. The WTRU of embodiment 11 comprising a unmasking unit to perform unmasking at least one of the received part 2 data and the received CRC bits with a mask.

13. The WTRU of embodiment 12 comprising a CRC unit for performing a CRC check on the unmasked CRC bits, the part 1 data and the part 2 data.

14. A WTRU as in any one of embodiments 12-13 wherein at least one of the received part 2 data and the received CRC bits are unmasked with a punctured WTRU ID of length equal to the CRC bits.

15. A WTRU as in any one of embodiments 12-14 wherein a portion of the WTRU ID is used to unmask received CRC bits and the remaining portion of the WTRU ID is used to unmask received part 2 data.

16. A WTRU as in any one of embodiments 12-15 wherein the unmasking unit generates a maximum minimum hamming distance mask using the WTRU ID and the generator matrix.

17. A WTRU as in any one of embodiments 12-16 further comprising a rate dematching unit to perform rate dematching on the received part 2 data and the received CRC bits.

18. The WTRU of embodiment 17 comprising a channel decoder for performing channel decoding on the received part 2 data and the received CRC bits after rate dematching, wherein the mask length is equal to the rate matched encoded part 2 data and CRC bits, and the demasking unit performs demasking prior to one of the channel decoding and rate dematching.

19. A method for encoding part 2 data of an HS-SCCH.

20. The method of embodiment 19 comprising generating CRC bits based on the part 1 data and the part 2 data, the CRC bits being appended to the part 2 data, the number of CRC bits being less than the WTRU ID.

21. The method of embodiment 20 comprising performing WTRU-specific masking of at least one of the part 2 data and the CRC bits with a mask.

22. The method of embodiment 21 comprising transmitting part 1 data and part 2 data with appended CRC bits after WTRU-specific masking.

23. The method as in any one of embodiments 21-22 wherein the mask is a punctured WTRU ID of length equal to the CRC bits.

24. A method as in any of embodiments 21-23 wherein the mask is a WTRU ID and a portion of the WTRU ID is used to mask CRC bits and a remaining portion of the WTRU ID is used to mask part 2 data.

25. The method as in any one of embodiments 21-24 further comprising generating a maximum minimum hamming distance mask using the WTRU ID and a generator matrix.

26. The method as in any one of embodiments 21-25 further comprising performing channel coding on the part 2 data and the CRC bits.

27. The method of embodiment 26 comprising performing rate matching on the encoded part 2 data and the CRC bits.

28. The method of embodiment 27 comprising generating a mask having a length equal to the rate matched coded part 2 data and CRC bits, wherein the WTRU-specific masking is performed after one of channel coding and rate matching.

29. A method for decoding high speed shared control channel (HS-SCCH) part 2 data.

30. The method of embodiment 29 comprising receiving part 1 data and part 2 data with appended CRC bits on the HS-SCCH, the number of CRC bits being less than the WTRU ID, at least one of the part 2 data and the CRC bits being masked with a mask.

31. The method of embodiment 30 comprising performing de-masking with a mask on at least one of the received part 2 data and the received CRC bits.

32. The method of embodiment 31 comprising performing a CRC check with the unmasked CRC bits, the part 1 data, and the part 2 data.

33. The method as in any one of embodiments 31-32 wherein at least one of the received part 2 data and the received CRC bits are unmasked with a punctured WTRU ID of length equal to the CRC bits.

34. A method as in any of embodiments 31-33 wherein received CRC bits are unmasked with a portion of the WTRU ID and received part 2 data is unmasked with the remaining portion of the WTRU ID.

35. The method as in any one of embodiments 31-34 further comprising generating a maximum minimum hamming distance mask using the WTRU ID and a generator matrix.

The method as in any one of embodiments 31-35 further comprising generating a mask.

37. The method of embodiment 35 comprising performing rate dematching on the received part 2 data and the received CRC bits.

38. The method of embodiment 37 comprising a channel decoder for performing channel decoding on the received part 2 data and the received CRC bits after rate dematching, wherein the mask length is equal to the rate matched encoded part 2 data and CRC bits, and the unmasking unit performs unmasking prior to one of the channel decoding and rate dematching.

39. A node B for encoding HS-SCCH part 1 data.

40. The node B of embodiment 39, comprising a channel encoder for performing channel encoding on the part 1 data.

41. The node B of embodiment 40 comprising a rate matching unit to perform rate matching on the encoded part 1 data.

42. The node-B of embodiment 41 comprising a masking unit to generate a maximum minimum hamming distance mask using the wtru id and the generator matrix and to perform masking of the rate matched encoded part 1 data with the mask.

43. The node B of embodiment 42 comprising a transmitter for transmitting the masked part 1 data.

44. The node-B of any of embodiments 42-43 wherein the mask is generated by (40, 16) encoding sixteen (16) bit WTRU IDs and has a minimum spacing of twelve (12).

45. A WTRU for decoding part 1 data of an HS-SCCH.

46. The WTRU of embodiment 45 comprising a receiver for receiving part 1 data.

47. The WTRU of embodiment 46 comprising a de-masking unit that generates a maximum minimum hamming distance mask using the WTRU ID and a generator matrix and performs de-masking on the received part 1 data with the mask.

48. The WTRU of embodiment 47 comprising a rate dematching unit to perform rate dematching on the unmasked part 1 data.

49. The WTRU of embodiment 48 comprising a channel decoder for performing channel decoding on the rate dematching the part 1 data.

50. A WTRU according to any of embodiments 47-49, wherein a mask is generated by (40, 16) encoding a sixteen (16) bit WTRU ID and the minimum spacing of the mask is twelve (12).

51. A method for encoding HS-SCCH part 1 data.

52. The method of embodiment 51 comprising performing channel coding on the part 1 data.

53. The method of embodiment 52 comprising performing rate matching on the encoded part 1 data.

54. The method of embodiment 53 comprising generating a maximum minimum Hamming distance mask using the WTRU ID and a generator matrix.

55. The method of embodiment 54 comprising performing masking of the rate matched coded portion 1 data with a mask.

56. The method of embodiment 55 comprising transmitting the masked portion 1 data.

57. The method as in any one of embodiments 54-56 wherein a mask is generated by (40, 16) encoding sixteen (16) bit WTRU IDs and the minimum spacing of the mask is twelve (12).

58. A method for decoding part 1 data of an HS-SCCH.

59. The method of embodiment 58, comprising receiving part 1 data.

60. The method of embodiment 59 comprising generating a maximum minimum Hamming distance mask using the WTRU ID and a generator matrix.

61. The method of embodiment 60, comprising performing unmasking of the received part 1 data with a mask.

62. The method of embodiment 61 comprising performing rate dematching on the unmasked portion 1 data.

63. The method of embodiment 62 comprising performing channel decoding on the rate dematching partial 1 data.

64. The method as in any one of embodiments 60-63 wherein a mask is generated by (40, 16) encoding sixteen (16) bit WTRU IDs and the minimum spacing of the mask is twelve (12).

Although the features and elements of the present invention are described in the preferred embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the preferred embodiments or in various combinations with or without other features and elements of the present invention. The methods or flow charts provided in the present invention may be implemented in a computer program, software, or firmware tangibly embodied in a computer-readable storage medium for execution by a general purpose computer or a processor. Examples of the computer-readable storage medium include read-only memory (ROM), random-access memory (RAM), registers, buffer memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM discs and Digital Versatile Discs (DVDs).

For example, suitable processors include: a general-purpose processor, a special-purpose processor, a conventional processor, a Digital Signal Processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) circuit, any Integrated Circuit (IC), and/or a state machine.

A processor in association with software may be used to implement a radio frequency transceiver for use in a Wireless Transmit Receive Unit (WTRU), User Equipment (UE), terminal, base station, Radio Network Controller (RNC), or any host computer. The WTRU may be used in conjunction with modules, implemented in hardware and/or software, such as a camera, a video camera module, a video phone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, and BluetoothA module, a Frequency Modulation (FM) radio unit, a Liquid Crystal Display (LCD) display unit, an Organic Light Emitting Diode (OLED) display unit, a digital music player, a media player, a video game player module, an Internet browser, and/or any Wireless Local Area Network (WLAN) module.

Claims (3)

1. A wireless transmit/receive unit (WTRU), comprising:

a processor configured to receive a High Speed Downlink Packet Access (HSDPA) signal, wherein the received HSDPA signal comprises data and a masked Cyclic Redundancy Check (CRC) field,

the processor is further configured to unmask the masked CRC field using the WTRU ID bits and perform a CRC check with the data and the unmasked CRC field, wherein the CRC field and the WTRU ID bits have different lengths.

2. A node B, the node B comprising:

a processor configured to:

retrieving Cyclic Redundancy Check (CRC) bits from a data block;

masking the CRC bits with wireless transmit/receive unit (WTRU) Identification (ID) bits of a WTRU for which the data block is intended, wherein the CRC bits and the WTRU ID bits have different lengths;

attaching the masked CRC bits to the data block; and

the data and masked CRC bits are transmitted via a physical channel for transmission as a High Speed Downlink Packet Access (HSDPA) signal.

3. A method implemented in a node B, the method comprising:

retrieving Cyclic Redundancy Check (CRC) bits from a data block;

masking the CRC bits with wireless transmit/receive unit (WTRU) Identification (ID) bits of a WTRU for which the data block is intended, wherein the CRC bits and the WTRU ID bits have different lengths;

attaching the masked CRC bits to the data block; and

the data block and masked CRC bits are transmitted via a physical channel for transmission as a High Speed Downlink Packet Access (HSDPA) signal.