Telefonaktiebolaget Lm Ericsson (Publ)

Lg Electronics Inc.

Samu Laaja

Sami Vilhonen

Jyri Sintonen

Harri Riihihuhta

A mobile terminal performing harmonic rejection includes a plurality of baseband units generating a baseband signal; a plurality of up-converters converting the baseband signal into a radio frequency (RF) signal; and a controller controlling phases of a plurality of signals applied to the plurality of baseband units and the plurality of up-converters. Meanwhile, the controller may perform at least one of a harmonic rejection mode, a first non-harmonic rejection mode for improving a signal-to-noise ratio (SNR), and a second non-harmonic rejection mode for improving linearity to provide a transmitting part having improved harmonic distortion characteristics and the mobile terminal having the transmitting part.

Method of controlling harmonics and mobile terminal performing thereof

An initial phase of each output signal generated by a plurality of radio frequency (RF) front-end circuits is determined by mixing an input signal with a mixing signal in a mixer of the corresponding RF front-end circuit. To that end, a time difference for each of the plurality of RF front-end circuits is determined by measuring a time difference between a reference signal (common to all of the RF front-end circuits) and the mixing signal of each RF front-end circuit. The initial phase for each output signal is then determined based on the measured time difference for the corresponding RF front-end circuit. Determining the initial phase in this manner accounts for any uncertainty of the phase when the RF front-end circuits are activated, enabling the phase of the corresponding antenna element to be accurately controlled.

Local oscillator phase synchronization for beamforming and MIMO

Systems and methods for mitigating interference in a Local Oscillator (LO) signal generated by a Phase-Locked Loop (PLL) are disclosed. In one embodiment, a system includes a PLL and an error compensation subsystem. The PLL includes a Controlled Oscillator (CO) that provides a LO output signal based on a control signal, a phase detector that generates a phase detector output signal that is indicative of a phase error between a feedback signal that is a function of the LO output signal and a reference signal, and a loop filter that filters the phase detector output signal to provide the control signal for the CO. The error compensation subsystem applies, based on the phase detector output signal, a phase rotation to a signal derived from the LO output signal to thereby compensate for a phase error in the signal resulting from a phase error in the local oscillator output signal.

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Turku, Finland

Samu Laaja