Method and Apparatus for Preamble Determination

Patent metadata

Field	Value
Publication number	US-2016174261-A1
Application number	US-201314900373-A
Country	US
Kind code	A1
Filing date	Jun 27, 2013
Priority date	Jun 27, 2013
Publication date	Jun 16, 2016
Grant date	—

Abstract

Methods and apparatuses for preamble determination have been provided. A method for transmitting a preamble by a user equipment to a base station is provided. The method comprises: selecting a random access resource for transmitting a preamble; determining one root sequence allocated to the random access resource based on a mapping relationship between root sequences and random access resources; generating a preamble based on the root sequence; and transmitting the preamble on the random access resource. The mapping relationship is established based on a rule that a random access resource carries preambles generated from a same root sequence.

First claim

1 - 18 . (canceled)

19 . A method for transmitting a preamble by a user equipment to a base station, said method comprising:
selecting a random access resource for transmitting a preamble; determining one root sequence allocated to said random access resource based on a mapping relationship between root sequences and random access resources; generating a preamble based on said root sequence; and transmitting said preamble on said random access resource;
wherein said mapping relationship is established based on a rule that a random access resource carries preambles generated from a same root sequence.

20 . The method of claim 19 , wherein according to said mapping relationship, an order of the root sequence is determined based on an order of an initial root sequence and an order of the random access resource within P radio frames, P≧1, and said P radio frames are used for carrying multiple preambles.

21 . The method of claim 20 , wherein the order of the root sequence is expressed by a logic index ID′ root of the root sequence, which is determined as:
ID′ root =ID root +X′,

wherein ID root is a logic index of the initial root sequence, X′ is a serial number indicating the order of the random access resource within the P radio frames, P is the minimum number of radio frames which are required for covering R root sequences, and R is the minimum number of root sequences which are required for generating the multiple preambles, R>1.

22 . The method of claim 21 , wherein said serial number X′ of the random access resource is determined as:
when R≧D RA ,

X
′

=

{

(

k



mod



P

)

×

D
RA

+
X

if




(

k



mod



P

)

×

D
RA

+
X

<
R

X

otherwise

;

when 0<R<D RA ,
X ′=( X mod R );

wherein D RA is a density of random access resource per radio frame; X is a local number of the random access resource within one radio frame; k is the system frame number, SFN, of a radio frame where the random access resource is located; and if D RA =0.5 and all the random access resources are only in radio frames which have odd SFN, said SFN k in the equation Eq. 6 is replaced with k′=k−1.

23 . The method of claim 22 , wherein said local number X of the random access resource is determined as:
when D RA ≧1, the local number X is numbered as 0, 1, . . . , D RA −1 sequentially in time first and then in frequency if and only if time multiplexing is not sufficient to hold all the D RA random access resources within one radio frame without overlap in time; and when D RA =0.5, the local number X is numbered as 0.

24 . A method for detecting a preamble received from a user equipment, said method comprising:
receiving a signal from a random access resource; determining one root sequence allocated to said random access resource based on a mapping relationship between root sequences and random access resources; and detecting a preamble carried on said random access resource based on said root sequence; wherein said mapping relationship is established based on a rule that a random access resource carries preambles generated from a same root sequence.

25 . The method of claim 24 , wherein according to said mapping relationship, an order of the root sequence is determined based on an order of an initial root sequence and an order of the random access resource within P radio frames, P≧1, and said P radio frames are used for carrying multiple preambles.

26 . The method of claim 25 , wherein the order of the root sequence is expressed by a logic index ID′ root of the root sequence, which is determined as:
ID′ root =ID root +X′,

wherein ID root is a logic index of the initial root sequence, X′ is a serial number indicating the order of the random access resource within the P radio frames, P is the minimum number of radio frames which are required for covering R root sequences, and R is the minimum number of root sequences which are required for generating the multiple preambles, R>1.

27 . The method of claim 26 , wherein said serial number X′ of the random access resource is determined as:
when R≧D RA ,

X
′

=

{

(

k



mod


Assignees

• Ericsson Telefon Ab L M

Inventors

• Yang Zhiyu
• Yan Junjie
• Zhou Zhenhong

Classifications

• H04L27/261 Primary

  Details of reference signals · CPC title

• H04W74/0833 Primary

  Random access procedures, e.g. with 4-step access · CPC title

• H04L5/0053 Primary

  Allocation of signalling, i.e. of overhead other than pilot signals · CPC title

• H04L69/22

  Parsing or analysis of headers · CPC title

• H04L5/0048

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title