hai, Ya...u r right...Some special combinations of 1's and -1's pocesses some wonderful correlation properties...These sequences are called Maximal Length (ML) sequences. There are some more variants like Gold codes, Kasami codes etc that too pocess similar properties... bye sameer On 11/28/05, Vincent Teo <vcteo@vcte...> wrote: > > Thx, regarding the PN sequence. They are only quasi-random bits generated > by an algorithm right? > So, if they are just bits of 1 or -1 what makes them possess such > correlation properties? Is it the combination of the bits that create such > properties? > > *"Sameer S.M" <sameerece@same...>* wrote: > > Hello, > Pilot signals are inserted in between (or at the beginning) of data > samples to aid channel estimation, synchronization and equalization. Mostly > these procedures requires the computation of auto and cross correlations of > the pilot samples. As PN sequences have good auto/cross correlation > properties, they are the simplest choices for pilot sequences. > > bye > Sameer > On 11/23/05, vcteo <vcteo@vcte...> wrote: > > > > Hi, i'm doing a project on OFDM and currently i'm just playing around > > and exploring with the HiperLan/2 demo that comes together with > > Simulink. > > > > I noticed at OFDM transmission, pilots are inserted and these pilots > > are single sample datas inserted regularly btwn the actual data. These > > pilots are generated by a Pseudo-random binary generator block. > > > > What is this block? What is the theory behind it? And why do we use > > this block to generate the pilots?

Thx, regarding the PN sequence. They are only quasi-random bits generated by an algorithm right? So, if they are just bits of 1 or -1 what makes them possess such correlation properties? Is it the combination of the bits that create such properties? "Sameer S.M" <sameerece@same...> wrote: Hello, Pilot signals are inserted in between (or at the beginning) of data samples to aid channel estimation, synchronization and equalization. Mostly these procedures requires the computation of auto and cross correlations of the pilot samples. As PN sequences have good auto/cross correlation properties, they are the simplest choices for pilot sequences. bye Sameer On 11/23/05, vcteo <vcteo@vcte...> wrote: Hi, i'm doing a project on OFDM and currently i'm just playing around and exploring with the HiperLan/2 demo that comes together with Simulink. I noticed at OFDM transmission, pilots are inserted and these pilots are single sample datas inserted regularly btwn the actual data. These pilots are generated by a Pseudo-random binary generator block. What is this block? What is the theory behind it? And why do we use this block to generate the pilots?

Hello, Pilot signals are inserted in between (or at the beginning) of data samples to aid channel estimation, synchronization and equalization. Mostly these procedures requires the computation of auto and cross correlations of the pilot samples. As PN sequences have good auto/cross correlation properties, they are the simplest choices for pilot sequences. bye Sameer On 11/23/05, vcteo <vcteo@vcte...> wrote: > > Hi, i'm doing a project on OFDM and currently i'm just playing around > and exploring with the HiperLan/2 demo that comes together with Simulink. > > I noticed at OFDM transmission, pilots are inserted and these pilots > are single sample datas inserted regularly btwn the actual data. These > pilots are generated by a Pseudo-random binary generator block. > > What is this block? What is the theory behind it? And why do we use > this block to generate the pilots?

Hi, i'm doing a project on OFDM and currently i'm just playing around and exploring with the HiperLan/2 demo that comes together with Simulink. I noticed at OFDM transmission, pilots are inserted and these pilots are single sample datas inserted regularly btwn the actual data. These pilots are generated by a Pseudo-random binary generator block. What is this block? What is the theory behind it? And why do we use this block to generate the pilots?