Abstract: In accordance with a method for single-carrier and multi-carrier reception, the following steps are executed: downconverting a received RF signal to in-phase (I) and quadrature (Q) channel signals each containing a plurality of sub-carriers at a low intermediate frequency (low-IF) and, if required, one sub-carrier or a single carrier centered around 0 Hz; filtering interfering signals outside of a frequency band of interest with analog lowpass filters in the I and Q channels; converting the I and Q channel signals to digital representations thereof; in the multi-carrier reception case, separating sub-carriers that are images of one another by quadrature downmixing the digital representations of the I and Q channel signals to baseband in the digital domain; and digitally adding or subtracting resulting I and Q signals to obtain one or both of an upper sideband and a lower sideband containing desired ones of the multi-carriers.

Abstract: A method and device for avoiding adjacent channel interference and reducing disconnections caused thereby, during communication between a mobile device and a base station in a wireless telecommunications network. The mobile device measures the strength of a received signal before the signal enters one or more selected filters, and compares the strength of the signal after the filtering, in order to estimate a power ratio of the adjacent channel interference to communication channel power. If the power ratio is greater than a threshold, then a handover is requested to an alternative communication channel available between the mobile device and either the base station or another base station.

Abstract: The invention relates to an arrangement and method for reducing losses at the transmitting end of a radio apparatus, especially one that operates in more than one system. An interfering transmitter is provided with two antenna filters one of which is a low-pass-type filter and the other a band-pass filter. The filter (BPF) with a higher stop-band attenuation is used only when the receiver (330, LNA) susceptible to interference is in receive state. At other times, the filter (LPF) with a lower stop-band attenuation and, hence, a lower pass-band attenuation, is used as the transmitting-end filter. Advantageously the selection between the different filters is realized using MEMS-type switches (SW31 to SW34). The invention minimizes the mean current consumption of the radio-frequency power amplifier (PA) of the said radio apparatus. The space required by and the production costs of the arrangement according to the invention are relatively small.