Shiu Tung Ho

US Patent:

20030076874, Apr 24, 2003

Filed:

Dec 3, 2002

Appl. No.:

10/308535

Inventors:

Daoben Li - Beijing, CN
Weidong Chen - San Jose CA, US
Haiyang Gao - San Jose CA, US
Shiu Ho - San Jose CA, US
Yongsheng Zhang - Beijing, CN
Yuanhua Deng - San Jose CA, US

Assignee:

Linkair Communications, Inc.

International Classification:

H04B001/707
H04B001/69

US Classification:

375/145000

Abstract:

A reverse synchronization method, which is used in a wireless system utilizing orthogonal spreading codes with Interference Free Window characteristic, wherein the transmission time of the signal from a remote unit is adjusted with respect to a predetermined Interference Free Window [-n, +n], such that the arrival time in a base station of the signal from the said remote unit falls within the said predetermined Interference Free Window. This eliminates inter-symbol interferences and multiple access interferences when multipath signals from a same remote unit and signals from different remote units arrive within an Interference Free Window.

US Patent:

20030083014, May 1, 2003

Filed:

Dec 3, 2002

Appl. No.:

10/308674

Inventors:

Daoben Li - Beijing, CN
Haiyang Gao - San Jose CA, US
Shiu Ho - San Jose CA, US
Yongsheng Zhang - Beijing, CN
Weidong Chen - San Jose CA, US
Yuanhua Deng - San Jose CA, US
Jianming Xu - San Jose CA, US

Assignee:

Linkair Communications, Inc.

International Classification:

H04B001/10

US Classification:

455/063000, 455/065000

Abstract:

In accordance with the present invention, a method is provided for a mobile station to select one cell site in a plurality of cell sites in cellular systems with an Interference Free Window. This method is based on measurement of the signal on the downlink. In preferred embodiments, a mobile station receives the downlink spread spectrum signals from a plurality of neighboring cells. By using a RAKE type correlator or matched filter, the signal energy and the multipath delay spread profile can be estimated at the mobile station. A new function is defined as the ratio of the multipath delay spread to the energy of the received signal. Minimizing the said function will result in a cell site that provides the best quality of service in a multipath propagation environment.

US Patent:

20030087603, May 8, 2003

Filed:

Dec 3, 2002

Appl. No.:

10/308514

Inventors:

Daoben Li - Beijing, CN
Haiyang Gao - San Jose CA, US
Shiu Ho - San Jose CA, US
Yongsheng Zhang - Beijing, CN
Weidong Chen - San Jose CA, US
Yuanhua Deng - San Jose CA, US

Assignee:

Linkair Communications, Inc.

International Classification:

H04B001/10
H04B015/00
H04B007/005
H04B007/01
H04B007/015

US Classification:

455/063000, 455/502000

Abstract:

A framing method and the synchronous wireless system therewith, wherein the method includes the steps of: partitioning the data stream into frames according to the frame length, in which the number of sub-frame in each frame can be determined by the periodicity of selected LA codes; forming each sub-frame by a plurality of time slots, in which the number of the said time slots can be determined by the number of pulses of the said LA codes, and the said time slot length varies with the variation of the pulse interval of the said LA codes; and filling in each time slot by modulation with the selected orthogonal spread spectrum codes. Different base stations from different, nearby cells shall be assigned different LA-CDMA codes so that adjacent cell interference can be reduced. While in nearby cells, the same spreading code can be assigned, therefore greatly reducing requirement for the number of spreading codes, as well as the requirement for the lengths of the spreading codes.