HF Radio Summary

HF Radio Power Calcs

EBR = Effective Bit Rate (Bytes/Second)
SS = Sample Size (Bytes/Sample)
PT = Preamble Time (Seconds)
SR = Sample Rate (Samples/Second)
GD = Group Duration (Seconds, how long are you grouping)
GS = Group Size (Samples/Group) = SR * GD
SP_{n} = Sample Power for Flight Interval n (seconds)
TS_{n} = Number of Transmissions per Second in Flight Interval n
TP = Power Used by Transmitter during TX (mW)
PB = Total Power Budget Required (mW-S)

SP_{n} = (SS/EBR) * (GS) + (PT)

TS_{n} = {{Interval Duration}*{SR}}/{Group Size}

PB = TP * sum{n}{}{SP_{n} * TS_{n}}

Example 1

Two Flight Intervals: Over the US, Not Over the US.
Total Flight Time = 72 Hours

For Flight Interval 1, Over the US:

Over the US is represented by a single large group. Group Size = {Samples/Minute} * {Minutes Over the US}

For this example, we will spend 330 Minutes over the US, 1 Sample / Minute * 5.5 hours = 330

EBR = 12 Bytes / Second
SS = 50 Bytes
PT = 30 Seconds
GS = 330 Samples

SP_{1} = (50/12) * (330) + (30) = 1405 Seconds

TS_{1} = {{330 minutes}*{{1 Sample}/{Minute}}}/{330} = 1

For Flight Interval 2, Not Over the US:

For this example, we will group for 15 minutes at a time. For this example, we spend 3990 minutes NOT over the US.

EBR = 12 Bytes/ Second
SS = 50 Bytes
PT = 30 Seconds
GS = (1 Sample/Minute) * (15 minutes) = 15 Samples

SP_{2} = (50/12) * (15) + (30) = 92.5 Seconds

TS_{2} = {{3990 minutes}*{{1 Sample}/{Minute}}}/{15} = 266

Putting it all together:

TP = 2000mW

PB = 2000mW * {{1405 Seconds}*{1} + {92.5 Seconds}*{266}} = 52020000 mW-S = 14450 mW-H

Assuming each battery cell delivers 1 volt at high current draw, and 1500 mA-H: 1500 mW-H / Cell = 10 Cells

hardware/radio/hf.txt · Last modified: 2010/10/21 00:31 by steamfire
 
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