Hybrid CDM/TDM signaling for packet acknowledgment method and apparatus

• US 20060007876A1
• Filed: 06/15/2005
• Published: 01/12/2006
• Est. Priority Date: 06/19/2003
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Via Telecom Co., Ltd.
• Inventors: Czaja, Stanislaw, Qian, Feng
• Granted Patent: US 7,359,365 B2
• Time in Patent Office: Days
• US Class Current: 370/320
• CPC Class Codes: H04L 1/1692 Physical properties of the supervisory signal, e.g. acknowledgement by energy bursts
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 2001/0092 Error control systems characterised by the topology of the transmission link
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365

Abstract

A common signaling channel (CSC) conveys signaling information units (SIUs) from a base station (BS) to each of a multiplicity (e.g., 1200) of different mobile stations (MSs). Implicit correspondence between particular CSC and data frames is facilitated by basing CSC frame duration on the data frame period. CSC frames are time multiplexed into K subframes, which are code division multiplexed (CDM) into J CDM branches to define J*K SIUs. CDM symbols (or sequences) representing each SIU may be diversely transmitted in different time slots, and/or using different OVSF codes or subchannels. Unique gain may be provided for each SIU. Subframe duration may ensure CDM code orthogonality despite fading. CDM symbol length may be an integer power of two, or have other values, such as 2^N*20 (e.g., 80). SIUs are typically relevant to BS-MS data packets, for example ACKs supporting H-ARQ for reverse link transmissions.

Claims

1. A method of transmitting a multiplicity of signaling information units (SIUs) from a base station (BS) to a corresponding multiplicity of receiving mobile stations (RMSs) via a common signaling channel (CSC), wherein data is communicated between each RMS and the BS via primary data frames of one or more other channels in a quantity substantially larger than is conveyed by corresponding SIUs, the method comprising:

a) identifying corresponding primary data frames to which the multiplicity of Slus are relevant, the primary frames having a primary frame duration;

b) transmitting the multiplicity of SIUs in a CSC frame having a duration shorter than or approximately equal to the primary frame duration during a time period selected to imply relevance of the SIU to the corresponding primary frames;

c) dividing the CSC frame into a multiplicity of subframes to effect time division multiplexing (TDM) of the CSC frame; and

d) for each of the multiplicity of SIUs, disposing within a subframe of the CSC frame a corresponding code division multiplexing (CDM) sequence representing such SIU and distinguishing it from other SIUs disposed in the same subframe.

2. The method of claim 1, wherein the CSC is distinguished from other channels transmitted from the BS within a substantially identical frequency range by a unique orthogonal variable spreading factor (OVSF) code.

3. The method of claim 2, wherein step (d) further comprises, for each of the multiplicity of SIUs, disposing two or more CDM sequences representing such SIU in different subframes within the CSC frame.

4. The method of claim 3, wherein the CSC OVSF channel includes a plurality of phase-distinguished subchannels.

5. The method of claim 4, further comprising transmitting the two or more CDM sequences of each of the SIUs on different phase-distinguished subchannels of the CSC OVSF channel.

6. The method of claim 5, wherein step (c) further comprises dividing the CSC frame into 15 subframes, and wherein the CDM sequences representing SIUs have a length of 80 code units.

7. The method of claim 5, wherein step (c) further comprises dividing the CSC frame into 16 subframes, and wherein the CDM sequences representing SIUs have a length of 64 code units.

8. The method of claim 5, wherein step (c) further comprises dividing the CSC frame into 18 subframes, and wherein the CDM sequences representing SIUs have a length of 64 code units.

9. The method of claim 3, wherein a number of SIU repetitions is the number of CDM sequences within a CSC frame representing a particular SIU directed to an RMS, and wherein the number of SIU repetitions for an SIU directed to a first RMS is different from the number of SIU repetitions for an SIU directed to a different second RMS.

10. The method of claim 5, wherein step (d) further comprises, for each of the SIUs, transmitting a corresponding representative CDM sequence during a first time period on an I-subchannel of the CSC, and transmitting the corresponding representative CDM sequence during a different second time period on a Q-subchannel of the CSC.

11. The method of claim 1, wherein the corresponding code division multiplexing (CDM) sequence that represents each of the multiplicity of SIUs has a length unequal to 2^N, N a positive integer.

12. The method of claim 11, wherein the corresponding code division multiplexing (CDM) sequence that represents each of the multiplicity of SIUs has a length equal to 2^N*20, N a non-negative integer.

13. The method of claim 1, wherein the corresponding code division multiplexing (CDM) sequence that represents each of the multiplicity of SIUs has a length equal to 2^N, N a positive integer.

14. The method of claim 1, wherein the SIUs comprise acknowledgement information relevant to automatic data retransmission procedures.

15. The method of claim 1, wherein each SIU transmitted from the BS to a particular RMS corresponds to a single CDM symbol and conveys only acknowledgment information regarding data transmitted from the particular RMS to the BS.

16. The method of claim 1, wherein the SIUs encoded within a particular CSC frame each convey information about data transmitted by a particular RMS during a primary frame having a common duration and a predetermined time offset with respect to the particular CSC frame.

17. Cellular communication system base station (BS) apparatus for high-speed data communication with a multiplicity of mobile station (MS) receivers, the apparatus comprising:

a) a data channel frame analysis module configured to determine duration and time alignment for primary frames of a multiplicity of data channels; and

b) a common signaling channel (CSC) signal preparation module configured to prepare a signal segment to convey a multiplicity of different signaling information units (SIUs), each corresponding to one of the multiplicity of data channels, for transmission from the BS as a particular frame on the CSC, the CSC signal preparation module including

i) a time division multiplexing (TDM) module configured to dispose SIUs into a plurality of different subframes within a CSC frame implicitly corresponding to the primary frames of the corresponding data channel,

ii) a coding module configured to encode each SIU as a code division multiplexed (CDM) symbol,

iii) a time diversity module configured to dispose a CDM symbol representing each SIU in a plurality of different subframes of the CSC frame,

iv) a plurality of CDM branch concatenation modules each configured to concatenate CDM symbols based on a particular orthogonal sequence cover for all subframes of the CSC frame as CDM branch frame sequences, and

v) a summation module configured to sum a plurality of CDM branch frame sequences to establish a signal segment conveying the CSC frame information.

18. The apparatus of claim 17, further comprising (b)(vi) a distribution module configured to distribute each CDM branch frame sequence between a plurality of different CSC subchannels.

19. The apparatus of claim 17, wherein the CDM symbol encoded for each SIU by the coding module has a length of 20*2^N code units, N a nonnegative integer.

20. The apparatus of claim 19, wherein the CSC utilizes a single orthogonal variable spreading factor (OVSF) code, the CSC frame has a duration of about 10 mS and is divided into 15 TDM subframes, N=2, each CDM branch frame sequence encompasses 30 CDM symbols including 2 CDM symbols representing each of 15 SIUs, and each CDM branch frame sequence is distributed between two different subchannels of the CSC channel.

21. The apparatus of claim 19, wherein the SIUs comprise acknowledgement information relevant to automatic data retransmission procedures, and each SIU is represented by a single CDM symbol.

22. The apparatus of claim 19, wherein for each SIU at least two representative CDM symbols are disposed in different CSC frames for diversity.

23. A method of transmitting a multiplicity of signaling information units (SIUs) from a base station (BS) to a corresponding multiplicity of receiving mobile stations (RMSs) via a common signaling channel (CSC), wherein data is communicated between each RMS and the BS via primary data frames of one or more other channels in a quantity substantially larger than is conveyed by corresponding SIUs, the method comprising:

a) a step for identifying corresponding primary data frames to which the multiplicity of SIUs are relevant, the primary frames having a primary frame duration;

b) a step for transmitting the multiplicity of SIUs in a CSC frame having a duration approximately equal to the primary frame duration during a time period selected to imply relevance of the SIU to the corresponding primary frames;

c) a step for dividing the CSC frame into a multiplicity of subframes to effect time division multiplexing (TDM) of the CSC frame; and

d) for each of the multiplicity of SIUs, a step for disposing within a subframe of the CSC frame a corresponding code division multiplexing (CDM) sequence representing such SIU and distinguishing it from other SIUs disposed in the same subframe.