Method for adaptively setting transmission parameters for a random access channel transmission uplink procedure in a wireless communication system

• US 20040264497A1
• Filed: 07/21/2004
• Published: 12/30/2004
• Est. Priority Date: 06/27/2001
• Status: Active Grant

• Current Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Wang, Yan, Zhao, Suli, Guan, Hao
• Granted Patent: US 7,013,146 B2
• Time in Patent Office: Days
• US Class Current: 370/465
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0015 characterised by the adaptation strategy
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04W 40/00 Communication routing or communication path finding
• CPC Class Codes: H04W 52/262 taking into account adaptive modulation and coding [AMC] scheme AMC per se H04L1/0001
• CPC Class Codes: H04W 52/36 with a discrete range or set of values, e.g. step size, ramping or offsets
• CPC Class Codes: H04W 52/48 during retransmission after error or non-acknowledgment
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 74/008 with additional processing of random access related information at receiving side
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

The present invention provides a method to enhance the RACH message transmission of a wireless communication systems. Therefore the known RACH procedure for uplink transmission is extended by additional steps in order to allow the usage of adaptive transmission parameters for uplink transmissions, preferably the usage of adaptive modulation and coding (AMC). This is advantageous because studies in high-speed downlink packet access show the possibility to increase the data rate of a downlink shared channel. The method according to the invention introduces a new RACH message preamble and enables the base station to estimate suitable adaptive transmission parameters like an AMC setting according to the current transmission conditions which are used during the RACH message transmission.

Claims

1. A method for using adaptive transmission parameters for a random access channel (RACH) transmission uplink, comprising the steps of:

selecting randomly one of available random access channel (RACH) sub-channels,

selecting randomly an available signature (C_sig,s(i)),

setting an initial random access channel (RACH) power level, estimated by a downlink power level, with a margin,

transmitting a random access channel (RACH) preamble with said random access channel (RACH) power level including said selected signature,

decoding an acquisition indicator (AI) on an acquisition indicator channel (AICH) to determine whether or not a base station has detected said random access channel (RACH) preamble,

in case no acquisition indicator (AI) on said acquisition indicator channel (AICH) is detected;

increasing said power level and retransmitting said random access channel (RACH) preamble with a new random access channel (RACH) power level increased at a power ramp step,

characterized by the additional steps of;

in case said acquisition indicator (AI) on said acquisition indicator channel (AICH) is detected;

transmitting a random access channel (RACH) message preamble including transmission conditions related data to enable a usage of adaptive transmission parameter setting for the random access channel (RACH) message part transmission;

wherein said transmission conditions related data includes a number of random access channel (RACH) preambles transmitted to said base station until said acquisition indicator (AI) is detected on said acquisition indicator channel (AICH) and includes said power ramp step used for transmitting said random access channel (RACH) preambles before said acquisition indicator (AI) is detected on said acquisition indicator channel (AICH),

receiving an indication message on said acquisition indicator channel (AICH), wherein said indication message contains an adaptive transmission parameter setting; and

using said adaptive transmission parameter setting for transmitting said message part of said random access channel (RACH) transmission.

2. A method according to claim 1, wherein said random access channel (RACH) message preamble includes channel condition related data.

3. A method according to claim 2, wherein said random access channel (RACH) message preamble consists of 256 repetitions of a length 16 signature P_s(n), n=0 . . . 15, defined as follows:

C_sig,s(i)=P₂(imodulo16), i=0,1, . . . , 4095

and a value vector B, defined as followed;

B=(b_m, . . . ,b₀), m∈

N,m>

2,

is spread with the signature C_sig,s(i) to form said new signature C′

_sig,s(i);

wherein said signature P_s(n) is chosen from a set of 16 Hadamard codes of length 16 and said value vector B codes said transmission conditions related data;

wherein a certain number of sub-values b_i are reserved for said coding of said number of random access channel (RACH) preamble transmissions and said remaining sub-values

are reserved for coding said power ramp step;

wherein said new signature C′

_sig,s(i) is used for said random access channel (RACH) message preamble including said transmission conditions related data.

4. A method according to claim 3, wherein said adaptive transmission parameter setting includes an adaptive modulation and coding setting.

5. A computer program for executing a method for using adaptive transmission parameters for a random access channel (RACH) transmission uplink, comprising program code means for carrying out the steps of claim 1 when said program is run on a computer, a network device, a mobile device, or an application specific integrated circuit.

6. A computer program product comprising program code means stored on a computer readable medium for carrying out the method of claim 1 when said program product is run on a computer, a network device, a mobile device, or an application specific integrated circuit.

7. An electronic device for wireless communication systems, comprising means adapted to perform a method according to claim 1.

8. A method according to claim 1, wherein said random access channel (RACH) message preamble consists of 256 repetitions of a length 16 signature P_s(n), n=0 . . . 15, defined as follows:

C_sig,s(i)=P_s(imodulo16), i=0,1, . . . ,4095

and a value vector B, defined as followed;

B=(b_m, . . . ,b₀), m∈

N,m>

2,

is spread with the signature C_sig,s(i) to form said new signature C′

_sig,s(i);

wherein said signature P_s(n) is chosen from a set of 16 Hadamard codes of length 16 and said value vector B codes said transmission conditions related data;

wherein a certain number of sub-values b_i are reserved for said coding of said number of random access channel (RACH) preamble transmissions and said remaining sub-values are reserved for coding said power ramp step;

wherein said new signature C′

_sig,s(i) is used for said random access channel (RACH) message preamble including said transmission conditions related data.

9. A method according to claim 1, wherein said adaptive transmission parameter setting includes an adaptive modulation and coding setting.

10. A method according to claim 2, wherein said adaptive transmission parameter setting includes an adaptive modulation and coding setting.

11. A computer program product comprising program code means stored on a computer readable medium for carrying out the method of claim 4 when said program product is run on a computer, a network device, a mobile device, or an application specific integrated circuit.

12. A computer program product comprising program code means stored on a computer readable medium for carrying out the method of claim 3 when said program product is run on a computer, a network device, a mobile device, or an application specific integrated circuit.

13. A computer program product comprising program code means stored on a computer readable medium for carrying out the method of claim 2 when said program product is run on a computer, a network device, a mobile device, or an application specific integrated circuit.