Researching the news release Sequans Introduces LTE Interference Rejection Technology issued in conjunction with the CTIA Convention in New Orleans this week I discovered some things I didn't know about LTE OFDM networks. The news release pointed me to a Sequans white paper, Mitigating Interference in LTE Networks, that explained that most LTE networks operate in a single frequency network configuration, unlike conventional cellular or 3G networks that use different groups of frequencies to avoid interference between adjacent cell sites. Because the different LTE base stations are transmitting different data to different users, they can interfere with each other. The interference can be rejected using nonlinear techniques that estimate the interference and subtract it from the received signal. It can also be rejected by using multiple antennas and combining them to create a directional antenna.
The Sequans Active Interference Rejection ("AIR") technology was co-developed with Sequans' technology partner ArrayComm using their antenna processing and interference management techniques combined with Sequans' expertise with OFDMA and MIMO receivers. The AIR equipped receiver permitted data bandwidth 3.5 times that of an industry standard maximum ratio combining (MRC) receiver.
LTE is one of the technologies that has been proposed for the next generation of digital broadcasting. A technology such as Sequans AIR could permit greater spectrum efficiency, greater coverage and a reduction in interference between a high power main transmitter and lower power boosters or repeaters.
