>>im planning to use a continuos loop in the transmitter, so it would
>send
>>the byte over and over again, and the transmitter would catch the
>byte and
>>do whatever it has activated.

Infrared remote-control links in consumer equipment usually use a 40 KHz
carrier and pulse-width modulation.  It's a good idea to use this sort of
scheme if possible since the most complicated part, the light detector
and analog signal processing in the receiver, is available as a low-cost
module.  Also, pushbutton- operated transmitters can be purchased off the
shelf.  Throughput of about 500-1000 baud and range on the order of 10
meters is possible.

The receiver processes the signal from the photodiode through a bandpass
filter and level detector.  When the level of 40 KHz energy is
sufficiently high, the digital output (usually active-low) turns on.  At
the transmitter, the LED is turned on and off at a 40 KHz rate (50% duty
cycle).  To send a bit, make a dropout of a few hundred us.  If the
dropout is close to the last one, call the bit a 1, if it is far, call it
a zero.  The start bit is a long time with no dropout.  For example, to
send 1101, transmit:

111111111111101110111011111101110
^-start------^   1   1      0   1

After the sequence leave the LED off for a while (depending on how long
the batteries in the transmitter need to last), and then repeat.  The
AM/AGC circuit in the receiver rejects noise best when the transmitter's
average power (inside the block) is high.  This is why long on times and
short off times are used.  When no signal is recieved most of the
reciever modules will output occasional short noise pulses, which the
start pulse detection logic immediately rejects.

The effective bit rate varies with the content of the data.  This is
usually not a problem.  The block rate needs to be defined for the worst
case data.  Some systems send the data both normal, then inverted, in the
block.  This makes the blocks constant length as well as providing some
redundancy.  If the response time can be slow (for example, pressing
buttons on a remote control), use a lot of redundancy: for example
receive 3 blocks and take action only if all 3 are the same.

>>
>>but how do i make the receiver recognize the start bit and stop
>bit????

A receiver for this type of code could be built around a routine that
measures how long the IR stays on:
   wait till IR on
   measure time
   wait till IR off
The result would be classed into 3 times: very long -> start bit, long ->
0 bit, short -> 1 bit.  It would also be good to time out the "wait till
IR on" and if it is longer than specified, reject the whole block and go
back to waiting for a start bit.

The core of the transmitter software would be a simple "send N cycles of
40 KHz" routine coupled with a routine to shift through the bits and call
the sending with one of 3 values of N.

Integrating the IR recption with the PIC's other duties can be done  in
various ways, but it does make it more complicated.  The IR receiver
module could be connected to the INT input, or a timer interrupt
state-machine polling of the IR input implemented.  Start with simple
software timing until you're able to make that work.