Frequency and phase offset compensation of modulated signals with symbol timing recovery

Abstract

Systems and methods are provided in which a wireless receiver can be configured to compensate frequency and phase offsets with joint symbol timing recovery of modulated signals transmitted across a channel, and it can include a transformation module configured to generate an error signal for an information signal representing the modulated signal received by the receiver. The transformation module can include a squaring module configured to square the information signal, thereby generating a squared signal, and a mixer configured to perform a complex multiplication of the squared signal by the local reference signal, and a downsampler. The transformation module can also be configured to extract and compensate frequency and phase offsets with joint symbol timing recovery.

Description

TECHNICAL FIELD[0001]The disclosed technology relates generally to communication systems, and more particularly, some embodiments relate to systems and methods for frequency and phase offset compensation with symbol timing recovery for received modulated signals.DESCRIPTION OF THE RELATED ART[0002]Wireless communication devices have become ubiquitous in today's society. Indeed, with the many continued advancements in communication technology, more and more devices are being introduced in both the consumer, commercial, and government sectors with advanced communications capabilities. Additionally, advances in processing power and low-power consumption technologies, as well as advances in data coding and modulation techniques have led to the proliferation of wired and wireless communications capabilities on a more widespread basis.[0003]For example, communication networks, both wired and wireless, are now commonplace in many home and office environments. Such networks allow various he...

AI Technical Summary

Benefits of technology

The patent text describes various solutions for compensating for frequency and phase offset errors in a radio frequency receiver. The technology can be used to determine the symbol start time and continuously estimate and compensate for these errors. The transformation module of the receiver generates an error signal by squaring the received signal and performing a complex multiplication with the local reference signal. The symbol timing estimator module, frequency offset estimator module, and phase offset estimator module then use this error signal to estimate the symbol timing, frequency offset, and phase error in the received signal. Overall, the technology allows for more accurate and efficient signal processing in the radio frequency receiver.

Problems solved by technology

Typically, transmitter and receiver oscillators have some frequency mismatch, which leads to frequency and phase offset errors.

Another source of such errors could be Doppler effects, which can arise in situations where the transmitter and receiver are in motion relative to one another.

Data-aided algorithms may require very long known sequences to estimate offsets, especially when the receiver operates at low signal-to-noise ratio (SNR) levels.

Accordingly, a drawback of this approach is that it loses information about the initial phase error and it cannot extract instantaneous phase offset.

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