barcodecontrol.com

aspx bar code High Rate WPAN in .NET Create QR Code 2d barcode in .NET High Rate WPAN




How to generate, print barcode using .NET, Java sdk library control with example project source code free download:
754 High Rate WPAN using none toassign none in asp.net web,windows applicationasp.net project to genarate barcode Start timing of supeframe -N 2/5 Industrial Superframe - N (2 56 Medium Access Slots , total 65,536usec). Superframe - N+1 Start timing of supeframe -N+1 Time Media Access Slot (256us) Beaconing slots (variable length) Beaconing slots (variable length). Figure 35.4: Ecma/WiMedia MAC superframe structure. To reduce the fra me error rate, the standard supports fragmentation of frames that can be reassembled at the receiver side. It supports 3 types of acknowledgements to verify the correct delivery of a frame based on the needs of the application: No-ACK, Imm-ACK and B-ACK policies. The No-ACK policy is suitable for frames that do not require guaranteed delivery.

The Imm-ACK policy is based on acknowledging each frame. The B-ACK acknowledges multiple frames at a time. If a source device does not receive the requested acknowledgement, then it may re-transmit the frame.

. 35.5 Overview of the WiMedia 1.0 PHY 35.5.1 Introducti on The WiMedia PHY is based on a 128-carrier OFDM system with band-hoping option.

The data rates range from 53.3 Mbps up to 480 Mbps. Different data rates are achieved through frequency-domain spreading (FDS), time-domain spreading (TDS), and forward error correction coding (FEC).

Figure 35.5 shows the simplified block diagram of a WiMedia OFDM modulator. The IFFT module receives a 128-point vector for frequency-domain (FD) preamble, header and payload symbols in frequency domain and transforms them into time domain.

The header and payload data are spread and coded according to the desired mode (see Section 35.5.4).

The time-domain (TD) preamble symbols are already defined in time, so these symbols are not processed by the IFFT module. The 128-point time domain vector at the output of MUX2 is then zero padded with 37 samples to form a 165-sample vector and represents one OFDM symbol. The complex data vector is then serialized and transformed into analog domain using a digital-to-analog converter (DAC) operating at, say, 528 MHz.

The resultant analog signal is low-pass filtered and then mixed up in frequency using the center frequency of the band for that particular symbol. An upsampling digital filtering with a 2-times over sampling DAC may be a better implementation to relax analog filtering requirements. The following subsections describe an overview of some of key features of the WiMedia PHY.

The readers are encouraged to consult the Ecma document [2] for a complete description of the specification. 35.5.

2 Band Hopping and Time Frequency Codes (TFCs) Due to the unique combination of power limitations (imposed by regulatory bodies) and the availability of wide spectrum (greater than 1 GHz worldwide), the UWB band (3.110.6GHz) is ideally suited for short range high data-rate applications.

However, using a. High Rate WPAN large bandwidth w ould correspondingly increase system complexity and cost due to the need for high speed circuits (such as A/D and D/A converters, filters, base-band processing modules, etc). The WiMedia PHY solves the issue of wide band requirement to a certain extent by using band hopping technique. This process is referred to as time-frequency hopping and involves changing the center frequency of the signal according to a predefined pattern.

The bandwidth of the signal in each hop is 528 MHz and the signal can hop in a maximum of 3 bands resulting in the total occupied bandwidth of about 1.5 GHz. As a result of this scheme, the bandwidth requirements on the analog front-end are relaxed.

Band-hopping also enables simultaneous operation of multiple links in this band within the same location providing increased spatial capacity.. TD preamble symbo none none ls FD preamble symbols encoding and spreading M U X 128 Point IFFT MUX 2 Zero suffix & GI Insertion P2S/ TDS. DAC Filter Header& Payload symbols Figure 35.5: Simp lified block diagram of WiMedia transmitter (represents the functionality of OFDM modulator)..

In order to enabl none for none e band-hopping mechanism, the allocated band for UWB operation is divided into 14 sub-bands as shown in Figure 35.6. The bands are further clustered into 5 band-groups, with 4 of them containing three bands each and one (Band Group #5) containing 2 bands.

Additional band-groups are also defined to meet other regulatory domain requirements. Once a device selects a band-group then it can hop only within its allocated bands, e.g.

devices operating in band-group #1 can only hop among bands 1, 2 and 3. The particular hopping pattern used is determined by the Time Frequency Code (TFCs) assigned to the device. Figure 35.

7 shows the table of the hopping patterns for different TFCs in band-groups 1 through 5. For example, band-group 1 and TFC 1 in this table indicates that the first OFDM symbol is transmitted in band #1, the second symbol in band #2 and so on and so forth. This pattern repeats every six OFDM symbols.

Similarly, TFC 3 in band-group 1 indicates that the first two symbols are transmitted in band #1, the next two symbols are transmitted in band #2 and the following two symbols are transmitted in band #3 and then the pattern repeats every six symbols. Band hopping is disabled for TFCs 5, 6 and 7 and therefore these TFCs are referred to as Fixed Frequency Interleaved (FFI) modes. On the other hand, TFCs 1 to 4 are referred to as Time Frequency Interleaved (TFI) modes.

. 3.432 GHz Band #1. 3.960 GHz Band #2. 4.488 GHz Band #3 Band Group#2 Band Group#3. 8.184 GHz Band #10. 8.712 GHz Band #11. 9.240 GHz Band #12. 9.768 GHz Band #13. 10.296 GHz Band #14. Band Group#1. Band Group #4. Band Group#5.
Copyright © barcodecontrol.com . All rights reserved.