Information Technology Reference
In-Depth Information
Pulse
type
HARQ
SS km
Rate
r
Length
rr
rrr
B
PHY
Frame
BCH
Parity Bits
HCS
SHR
PHR
PSDU
Transmit order
Fig. 1.
Ultra wideband Physical layer Frame Format
rate applications, UWB physical layer is best suitable compared to other physi-
cal layers because of larger bandwidth (500 MHz) availability [6]. In this paper,
two architectures are considered for UWB PHY baseband transmitter designs
for WBAN applications. The details of implementations of the architectures and
their differentiating features are explained in section III of this paper. We also
discussed the hardware implementation of each block in the baseband processor.
To the best of our knowledge, it is the first time an architecture for the standard
is implemented.
2 Ultra Wideband PHY Specification
The operating frequency bands of UWB PHY layer divided into two band groups:
low band (3.244 to 4.742 GHz) and high band (6.240 to 10.23 GHz). The low
band is divided into 3 channels, high band into 8 channels and each channel's
bandwidth is 499.2 MHz. The standard [5] defines two modes of operations:
default mode and high QOS mode. The default mode shall be used in medical
and non-medical applications and the high QOS mode in high priority medical
applications. In this paper, default mode implementation is considered.
The PLCP layer constructs the UWB PHY frame format or physical layer
protocol data unit (PPDU) by concatenating the synchronization header (SHR),
physical layer header (PHR) and physical layer service data unit (PSDU) respec-
tively, as shown in Fig. 1. Detailed descriptions of SHR, PHR and PSDU are
given below.
2.1 Synchronization Header
The synchronization header (SHR) shall be divided into two parts: Preamble, in-
tended for timing synchronization, packet detection, and carrier frequency offset
recovery; The frame delimiter, which is used for frame synchronization[5].
