The present disclosure provides a method and system for fine estimation of a local oscillator frequency offset of a received signal at a coherent receiver, by evaluating the probability mass function of the signal phase of output symbols at different frequencies. A screen change detecting unit watches the screen image data and detects a change of the screen image data. Each of the first cutting edges is formed on an intersecting ridge portion between the first end surface and a corresponding side surface portion so as to curve on a plane orthogonal to the axis. Present invention effectively releases the undesired torque and restores the cable to its neutral and relaxed state, so that the fitness equipment will experience less malfunctioning, and user safety is enhanced. The first electrode and the second electrode are disposed in the transmissive portion and at least the first electrode and the third electrode are disposed in the reflective portion. The ICI control method includes receiving an uplink signal at a base station and extracting inter-cell interference amount information from the uplink signal, generating uplink control information based on the extracted inter-cell interference amount information, and transmitting the uplink control information to a terminal in a neighboring cell.