Improving outdoor to indoor coverage by use of TD-LTE in-band relay

Indoor coverage is essential to the mobile user experience, because the signal power from the remote macro base stations is seriously weakened after penetrating the walls. Traditional indoor coverage system is a good solution but it can not be deployed in all the buildings. In order to enhance the received signal power inside the building, a relay can be used in a long term evolution (LTE) system. The benefits of relay are: it can be deployed anywhere quite near to the building since it uses wireless backhaul with less position limitation, and thus it can amplify the transmitting power due to the nearby position to the building comparing to the remote macro base stations. Then even with penetration loss, the received signal power inside the building is still high enough to carry traffic. The field test results show that a TD-LTE relay can improve the indoor received signal power and traffic obviously, and thus it´s a good solution to enhance outdoor to indoor coverage.