IBI (Inter-block interference)

Inter-block interference (IBI) is a phenomenon that occurs in digital communication systems, particularly in block-based transmission schemes. In this type of transmission, data is divided into blocks and transmitted over a channel in a sequential manner. The receiver then attempts to reconstruct the original data by combining the received blocks.

IBI occurs when the transmitted blocks interfere with each other, causing errors in the received data. This interference can be caused by a number of factors, including the use of a limited bandwidth channel, imperfect synchronization between the transmitter and receiver, and the presence of multipath propagation in the channel.

One of the main causes of IBI is the use of a limited bandwidth channel. When the available bandwidth is limited, the transmitted signal is spread out over a wider frequency range, which can result in overlapping between adjacent blocks. This overlapping can cause errors in the received data, as the receiver may not be able to distinguish between the different blocks.

Another cause of IBI is imperfect synchronization between the transmitter and receiver. If the receiver is not properly synchronized with the transmitter, it may receive data from one block while it is still processing data from a previous block. This can cause errors in the received data, as the receiver may not be able to properly decode the received signal.

Multipath propagation is another factor that can cause IBI. In a multipath channel, the transmitted signal can take multiple paths to reach the receiver. This can cause the signal to arrive at the receiver at different times, resulting in interference between adjacent blocks. This interference can cause errors in the received data, as the receiver may not be able to properly decode the received signal.

There are several techniques that can be used to mitigate IBI in digital communication systems. One such technique is channel coding, which involves adding redundancy to the transmitted data in order to improve the ability of the receiver to detect and correct errors. Another technique is interleaving, which involves rearranging the transmitted data in a way that reduces the likelihood of adjacent blocks interfering with each other.

In addition to these techniques, there are also a number of advanced modulation and coding schemes that can be used to mitigate IBI. These schemes are designed to optimize the use of the available bandwidth and reduce the likelihood of interference between adjacent blocks.

Overall, IBI is a complex phenomenon that can have a significant impact on the performance of digital communication systems. By understanding the causes of IBI and implementing effective mitigation techniques, it is possible to improve the reliability and performance of these systems.