A method for wireless communications by a first type of user equipment, comprising: detecting, within one or more narrowband regions of wider system bandwidth, a primary synchronization signal, PSS, generated utilizing a first code sequence and a cover code applied to the first code sequence over a first number of symbols within one or more subframes; performing a maximum-likelihood time offset estimation based on the PSS, wherein the time offset is uncorrelated with a frequency offset; performing an initial time synchronization and a frequency synchronization based on the PSS; detecting, within the one or more narrowband regions, a secondary synchronization signal, SSS, generated based on a second code sequence over a second number of symbols within the one or more subframes; and performing fine time synchronization based on the SSS, to refine the initial time and frequency synchronization, wherein the fine time synchronization comprises: performing a maximum-likelihood timing offset estimation correction by coherently combining all co-phased symbol pairs according to a pattern of the cover code, wherein a range of the combining spans across the one or more subframes, wherein the combining of the co-phased symbol pairs comprises performing autocorrelation between delayed samples of the PSS, wherein a lag size of the delayed samples is a configurable parameter based on PSS time domain resource allocation; and normalizing a cost function for the timing offset by a power of the PSS sequence to reduce sensitivity to signal to noise ratio, SNR, levels. detecting, within one or more narrowband regions of wider system bandwidth, a primary synchronization signal, PSS, generated utilizing a first code sequence and a cover code applied to the first code sequence over a first number of symbols within one or more subframes; performing a maximum-likelihood time offset estimation based on the PSS, wherein the time offset is uncorrelated with a frequency offset; performing an initial time synchronization and a frequency synchronization based on the PSS; detecting, within the one or more narrowband regions, a secondary synchronization signal, SSS, generated based on a second code sequence over a second number of symbols within the one or more subframes; and performing fine time synchronization based on the SSS, to refine the initial time and frequency synchronization, wherein the fine time synchronization comprises: performing a maximum-likelihood timing offset estimation correction by coherently combining all co-phased symbol pairs according to a pattern of the cover code, wherein a range of the combining spans across the one or more subframes, wherein the combining of the co-phased symbol pairs comprises performing autocorrelation between delayed samples of the PSS, wherein a lag size of the delayed samples is a configurable parameter based on PSS time domain resource allocation; and normalizing a cost function for the timing offset by a power of the PSS sequence to reduce sensitivity to signal to noise ratio, SNR, levels. performing a maximum-likelihood timing offset estimation correction by coherently combining all co-phased symbol pairs according to a pattern of the cover code, wherein a range of the combining spans across the one or more subframes, wherein the combining of the co-phased symbol pairs comprises performing autocorrelation between delayed samples of the PSS, wherein a lag size of the delayed samples is a configurable parameter based on PSS time domain resource allocation; and normalizing a cost function for the timing offset by a power of the PSS sequence to reduce sensitivity to signal to noise ratio, SNR, levels.