The output of the matched filter will have a maximum peak value if its coefficients are modulated by the carrier with the correct integer CFO. Please try the request again. Those non-idealities include sampling clock offset, IQ imbalance, power amplifier, phase noise and carrier frequency offset nonlinearity. Generated Sun, 16 Oct 2016 02:25:03 GMT by s_ac15 (squid/3.5.20)

Hence, the rotated signal samples are stored in the circular buffer 62 in a manner such that any data sample within a prescribed duration (e.g., one maximum-length data packet) can be The advantages of the present invention may be realized and attained by means of instrumentalities and combinations particularly pointed in the appended claims. OFDM Multicarrier Wireless Networks: A Practical Approach defines and explains the mathematical concepts behind OFDM necessary for successful OFDM WLAN implementations. To gain an effective CFO estimate, the BLUE estimator uses a weighted average of all ϕ ( u ) {\displaystyle \phi (u)} and computes Δ f ^ / f S =

BRIEF DESCRIPTION OF THE INVENTION The object of this invention is to provide a method by means of which a frequency error of a signal to be received can be determined In addition to the coarse and fine frequency offset estimator 58, the phasor circuit 60 and the channel estimator 70, the receiver module 50 also includes a timing synchronization module 72, It is obvious to a person skilled in the art that as technology progresses the basic idea of the invention can be implemented in a variety of ways. L.

The received signal also suffers from sampling clock offset (SCO), which may cause a gradual drift of the safe DFT window in addition to extra phase shift in the received frequency-domain Zhang, H. The receiver module 50, implemented as a digital circuit, includes an I/Q mismatch compensation module 52 that receives detected wireless signal samples (in digital form) from an R/F analog front end In the ideal situation, the frequency of the signal to be received is known accurately, and likewise, the locations of the symbol sequences in the signal to be received are known.

Terry is the vice-chair of the IEEE 802.11 Task Group and serves as a technical reviewer for several conference and journal publications of the IEEE in wireless communications. In the FIG. 1, the curve 3 illustrates the received signal, from which modulation is removed, and the difference of the phases of the corresponding sampling points of the successive symbol a hundred successive symbol sequences are sampled one sample each per every sampling point. In the 6MHz DVB-T system, assuming that the oscillator deviation is within ±20 ppm and the carrier frequency is around 800MHz, the maximum CFO can be up to ±38 subcarrier spacing

Numbers correspond to the affiliation list which can be exposed by using the show more link. Dr. Channel information is obtained by the channel estimator 70 from the long training sequence in the IEEE 802.11 preamble; the channel information is used by the channel estimator 70 to estimate Your cache administrator is webmaster.

BRIEF DESCRIPTION OF THE DRAWINGS In the following the invention will be described in greater detail in connection with preferred embodiments with reference to the accompanying drawings of which FIG. 1 Juha Heiskala is a senior research engineer at Nokia Research Center in Dallas, TX. Please introduce links to this page from related articles; try the Find link tool for suggestions. (June 2015) Carrier frequency offset (CFO) is one of many non-idealities in baseband receiver design. Tests show this indicator to be both accurate and reliable.This technique was first observed by Stephen and Steven for an error estimation for buckling and has been extended in this paper

The coefficients of the matched filter are the complex conjugate of the long preamble and they are modulated by a sinusoidal wave whose frequency is a possible integer CFO mentioned above. The first and second subgroups each have an equal number of symbol subgroup positions. Advanced Search | About Patents.com | Login | Patent Resources | Contact Us | Terms of Use Copyright 2008 - 2015 Patents.com ERROR The requested URL could not be retrieved The All rights reserved.

Then, the CFO is estimated based on the phase of delay correlation of weighted Signals.For integer CFO, frequency-domain cross-correlation and frequency-domain PN correlation can be used with slight modification. Attorney Review -- Have your application reviewed by a Patent Attorney. The decoding portion 80 includes a digital slicer module 82, a deinterleaver 84, and a Viterbi decoder 86. Hence, a comparison between symbols of the subgroups 118 a and 118 b that share the same corresponding subgroup position enables a uniform time-delayed evaluation between the pilot tones, the uniform

In the following, algorithms for resolving such frequency ambiguity in the estimated carrier frequency offset will be presented. According to the IEEE 802.11a/g specification, the physical layer data packet should include a short training sequence, a long training sequence, a signal field (indicating the data rate and length of The rotor circuit 56 is configured for compensating between a local receiver carrier frequency (i.e., local oscillator) and the remote transmitter carrier frequency (i.e., remote oscillator) used to transmit the wireless As a result, a single CFO set is to be estimated for the multiple receive antennas.

He has 12 years of experience working in wireless communications, including tenures at NASA Glen Research Center and Texas Instruments, Inc. In the FIG. 1, the curve 1 illustrates the frequency signal of the receiver and the curve 3 that of the transmitter. In addition, each symbol has a corresponding subgroup position within its subgroup: in the case of subgroup 118 a, the symbol 112 I (Sym1) is at position “1”, the symbol 112 Inventors: Huttunen; Mikko (Espoo, FI) Assignee: Nokia Networks Oy (Espoo, FI) Appl.

The phase shifts in the received frequency-domain Signals caused by the CFO are identical at all subcarriers provided that the ICI is ignored. The receiver of claim 10, wherein the state machine is configured for initially setting the size of the prescribed group to eight (8) symbols. 12. The complex products for all the symbol subgroup positions are accumulated (i.e., summed) by the complex summation circuit 108, resulting in an accumulated complex value 122. The TETRA system employs .pi./4-DQPSK(Differential Quaternary Phase Shift Keying) modulation, whereby a digital signal is modulated to a carrier in two-bit sequences in such a way that a specific phase shift

Particularly in mobile communication systems, in which intercommunicating devices have no separate synchronizing connection, but each device comprises an oscillator of its own, the frequencies of the devices need to be