Hughes Electronics Corporation

The Directv Group, Inc.

Kamran Etemad

Khalid Karimullah

Lin-Nan Lee

Feng-Wen Sun

A communication system is used to transmit and receive data on a plurality of relatively narrow-band signals and wideband signals. The two signal types share a common electromagnetic spectrum by employing spreading gain and maintaining orthogonality between simultaneously transmitted wideband and narrow-band signals. Signal orthogonality is maintained by selectively choosing orthogonal codes and aligning or spacing a wideband carrier frequency with respect to the narrow-band carrier frequencies in accordance with the ratio of the wideband to the narrow-band chip frequencies. A pilot signal is preferably transmitted contemporaneously with the transmission of the first spread signal, and a control date signal, associated with a plurality of users on the first bandwidth, is transmitted on a common control channel using a single Walsh code that is shared by a plurality of users in a TDMA protocol.

Method for transmitting wideband signals via a communication system adapted for narrow-band signal transmission

A system and method for optimizing random access control, and for optimizing transmission efficiency of data packets over reverse common channels between access terminals and a base station, in a wireless communications system. In the communications system, at least one of the access terminals is adapted to transmit at least a portion of an access data packet to the base station, and the base station is adapted to receive the portion of the access data packet and, in response, to transmit a message for receipt by the plurality of access terminals which indicates receipt of the access data packet portion by the base station and identifies the access terminal from which said access data packet portion is received. The message can control the other access terminals to refrain from transmitting an access data packet, while indicating receipt of the access data packet portion to the certain access terminal from which the access data packet portion had been transmitted. The base station can also provide power control signals to control transmission power of that certain access terminal, and to control that certain access terminal to transmit over certain reverse channels. Accordingly, interference between access data packets being transmitted by multiple access terminals and being received in the same time slot by a base station in a wireless communications system can also be minimized.

SYSTEM AND METHOD FOR USING INHIBIT SENSE MULTIPLE ACCESS (ISMA) PROTOCOL AND A CAPTURE MESSAGE TO OPTIMIZE RANDOM ACCESS CONTROL AND DATA PACKET COMMUNICATION BETWEEN ACCESS TERMINALS AND A BASE STATION OVER A WIRELESS REVERSE COMMON CHANNEL

A communication system is used to transmit and receive a plurality of relatively narrow-band signals and wideband signals. The two signal types share a common electromagnetic spectrum by employing spreading gain and maintaining orthogonality between simultaneously transmitted wideband and narrow-band signals. Signal orthogonality is maintained by selectively choosing orthogonal codes and aligning or spacing a wideband carrier frequency with respect to the narrow-band carrier frequencies in accordance with the ratio of the wideband to the narrow-band chip frequencies. A pilot signal is preferably transmitted contemporaneously with the transmission of the first spreaded signal, and a control data signal, associated with a plurality of users on the first bandwidth, is transmitted on a common control channel using a single Walsh code that is shared by a plurality of users in a TDMA protocol. Further, if the length of the message intended for transmission by the wideband transceivers is below a message length threshold, the message can be transmitted using a common access channel shared by the wideband transceivers. Still further, by adapting the data transmission rate, in response to the data error rate and transmitter power level, the transmission range and/or the data transmission rate can be optimized.

Growing community of inventors

Gaithersburg, MD, United States of America

Kamran Etemad