Network signaling compression for bit loading

Link adaptation technology has been introduced in new generation transmission systems such as 3-G or 4-G optimizing both their throughput and their power consumption. The adaptation of radio configuration requires information about the radio link quality. The information most be exchanged between the access point and the mobile terminal, leading to an associated dealing load, whose amount may decrease the system transmission efficiency. A mechanism for reducing the amount of dealing information has to be designed for increasing the overall system capacity (more users, more available bandwidth). This paper addresses multi-carrier systems whose link adaptation is called out by means of bit load tag algorithms. However, the associated signaling load increases quickly with the number of sub-curriers, modulation schemes and users. These bit-loading vectors are considered a-priori known at the receiver, and almost no literature concerning transmission of such information is available. In realistic transmission systems, correlation exists in time due to Doppler effect, and in frequency due to multi-path delay spread. We intend to exploit this two fold redundancy to decrease the signaling information load related to the power vector data for bit loading. A compression system for both bit allocation and power allocation of the bit loading is proposed. The performance of such compression system is then evaluated.