Filtering and guard band for non-synchronized transmission

• US 20080240028A1
• Filed: 01/07/2008
• Published: 10/02/2008
• Est. Priority Date: 01/08/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Khan, Farooq, Ding, Yinong
• Granted Patent: US 8,223,700 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

A wireless terminal capable of communicating with a wireless communication system comprised of a plurality of wireless terminals and a plurality of base stations. The wireless terminal selects a sequence from a group of certain sequences for random access. At least one sub-carriers on an uplink channel including at least one data channel is allocated for at least one random access channel. Each data channel includes a continuous set of data sub-carriers. The wireless terminal then filters the at least one random access channel by applying a Raised Cosine filter, maps the selected sequence to the at least one random access channel to generate a random access channel signal, and transmits the random access channel signal to a base station.

Claims

1. A method for communication, the method comprising the steps of:

enabling a wireless terminal to access a wireless communication system comprised of a plurality of wireless terminals and a plurality of base stations by selecting a sequence from a group of certain sequences for random access;

allocating at least one sub-carriers on an uplink channel for at least one random access channel, with the uplink channel comprising at least one data channel, and each data channel comprising a continuous set of data sub-carriers;

filtering the at least one random access channel by applying a Raised Cosine filter;

mapping the selected sequence to the at least one random access channel to generate a random access channel signal; and

transmitting the random access channel signal to one of said base stations.

2. The method of claim 1, comprised of the Raised Cosine filter having a roll-off coefficient of approximately 0.12.

3. The method of claim 1, comprised of, when the at least one random access channel comprising a continuous set of frequency sub-carriers,

inserting two guard bands at each side of the combination of the random access channels, with each of the two guard bands comprising a continuous set of data sub-carriers;

and

filtering a combination of the two guard bands and the random access channels by applying the Raised Cosine filter.

4. The method of claim 3, comprised of the Raised Cosine filter having a roll-off coefficient of approximately 0.12.

5. The method of claim 3, comprised of the two guard bands being constructed from a data resource block.

6. The method of claim 1, comprised of the group of certain sequences comprising a Zadoff-Chu sequence and a Generalized Chirp-Like sequence.

7. A wireless terminal, with the wireless terminal,

accessing a wireless communication system comprised of a plurality of wireless terminals and a plurality of base stations by selecting a sequence from a group of certain sequences;

allocating at least one sub-carriers on an uplink channel for at least one random access channel, with the uplink channel comprising at least one data channel, and each data channel comprising a continuous set of data sub-carriers;

filtering the at least one random access channel by applying a Raised Cosine filter;

mapping the selected sequence to the at least one random access channel to generate a random access channel signal; and

transmitting the random access channel signal to one of said base stations.

8. The wireless terminal of claim 7, comprised of the Raised Cosine filter having a roll-off coefficient of approximately 0.12.

9. The wireless terminal of claim 7, with, when the at least one random access channel comprising a continuous set of frequency sub-carriers,

the wireless terminal inserting two guard bands at each side of the combination of the random access channel signals, With each of the two guard bands comprising a contiguous set of data sub-carriers;

and

the wireless terminal applying the Raised Cosine filter to filter a combination of the two guard bands and the random access channels.

10. The wireless terminal of claim 9, comprised of the Raised Cosine filter having a roll-off coefficient of approximately 0.12.

11. The wireless terminal of claim 9, comprised of the two guard bands being constructed from a data resource block.

12. The wireless terminal of claim 7, comprised of the group of certain sequences comprising a Zadoff-Chu sequence and a Generalized Chirp-Like sequence.

13. A base station, with the base station,

enabling a wireless terminal to access a wireless communication system comprised of a plurality of wireless terminals and a plurality of base stations by instructing the wireless terminal to select a sequence from a group of certain sequences;

instructing the wireless terminal to allocate at least one sub-carriers on an uplink channel for at least one random access channel, with the uplink channel comprising at least one data channel, and each data channel comprising a continuous set of data sub-carriers;

instructing the wireless terminal to filter the at least one random access channel by applying a Raised Cosine filter;

instructing the wireless terminal to map the selected sequence to the at least one random access channel to generate a random access channel signal; and

scheduling the wireless terminal to transmit the random access channel signal to the base station.

14. The base station of claim 13, comprised of the Raised Cosine filter having a roll-off coefficient of approximately 0.12.

15. The base station of claim 13, with, when the at least one random access channel comprising a continuous set of frequency sub-carriers,

the base station instructing the wireless terminal to insert two guard bands at each side of the combination of the random access channel signals, with each of the two guard bands comprising a contiguous set of data sub-carriers;

and

the base station-instructing the wireless terminal to apply the Raised Cosine filter to filter a combination of the two guard bands and the random access channels.

16. The base station of claim 15, comprised of the Raised Cosine filter having a roll-off coefficient of approximately 0.12.

17. The base station of claim 15, comprised of the two guard bands being constructed from a data resource block.

18. The base station of claim 13, comprised of the group of certain sequences comprising a group of a Zadoff-Chu sequence and a Generalized Chirp-Like sequence.