公开(公告)号：BR9901054A

公开(公告)日：2000-01-18

申请号：BR9901054

申请日：1999-04-14

Applicant: LUCENT TECHNOLOGIES INC

Inventor： RAMESH NALLEPILLI SUBRAMANIAN

IPC: H04B7/06 ,  H04B7/26 ,  H04Q7/30

Abstract: A wireless telecommunications system is disclosed that mitigates multipath fading through an improvement in transmit diversity. Furthermore, embodiments of the present invention are well-suited for use with all forward channel multiplexing schemes (e.g., frequency-division multiplexing, time-division multiplexing, code-division multiplexing, etc.) and all modulation techniques (e.g., amplitude modulation, frequency modulation, phase modulation, etc.). An illustrative embodiment of the present invention comprises: a signal inverter (613) for inverting and alternately not-inverting a first signal in accordance with a schedule (615) to create a second signal; a first antenna for transmitting the first signal; and a second antenna for transmitting the second signal.

公开(公告)号：BR9906121A

公开(公告)日：2000-08-15

申请号：BR9906121

申请日：1999-11-03

Applicant: LUCENT TECHNOLOGIES INC

Inventor： MEYERS MARTIN HOWARD ,  RAMESH NALLEPILLI SUBRAMANIAN ,  WU XIAO CHENG ,  WANG JIAN-REN

IPC: H04B7/005 ,  H04L12/28 ,  H04W52/50 ,  H04W74/08 ,  H04Q7/38

Abstract: Disclosed is a method for significantly reducing the amount of collisions of access messages on reverse link Random Access Channels (RACH) by multiple mobile-stations attempting to gain system access concurrently, thereby greatly improving access performance in wireless communications system using existing multiple access schemes. The improvement is achieved by transmitting a probe message instead of an access message over the RACH, wherein the probe message is shorter in length than the access message. Transmission of the probe messages utilizes less of the RACH than the longer access messages, thereby reducing the chance of collisions with other probe messages. The access message is subsequently sent on a traffic channel or a control channel designated by a base station receiving the probe message. Alternately, a data burst is transmitted over the designated traffic channel or control channel.

公开(公告)号：BR9906122A

公开(公告)日：2000-09-19

申请号：BR9906122

申请日：1999-11-05

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LI QUINN ,  RAMESH NALLEPILLI SUBRAMANIAN

IPC: H04B1/707 ,  H04B7/26 ,  H04J13/10 ,  H04Q7/38

Abstract: A complex spreading and/or scrambling code sequence ("scrambling code sequence") generation system uses a first complex code sequence having at least two components and a second complex code sequence having at least two components. The components of the first complex code sequence are respectively mixed with the corresponding components of the second complex code sequence to generate the complex scrambling code sequence. In doing so, an offset between the components of the complex scrambling code sequence is achieved for the same and/or different users. For example, the complex spreading code sequence generation system can use a long code generator which produces a long code sequence produced from the inner product of a code vector and a user mask. The long code sequence is provided to an I path and a Q path. To produce a complex long code sequence, the long code sequence on the Q path is delayed to produce a second long code sequence on the Q path or a Q component of the complex long code sequence. On the I path, the I long code sequence or the I component of the complex long code sequence is multiplied with an I component of a short code sequence to produce the I component of the complex scrambling code sequence. On the Q path, the Q long code sequence is multiplied with a Q component of the short code sequence to produce the Q component of the complex scrambling code sequence. As such, the offset between the components of the complex scrambling code sequence between different and/or the same user is at least the period of the short code. The complex scrambling code sequence can be used for spreading, scrambling, de-spreading or de-scrambling an information signal.